tag:theconversation.com,2011:/au/topics/forensic-entomology-1158/articlesForensic entomology – The Conversation2023-07-30T20:08:31Ztag:theconversation.com,2011:article/2074182023-07-30T20:08:31Z2023-07-30T20:08:31ZSecrets wrapped in fabric: how our study of 100 decomposing piglet bodies will help solve criminal cases<figure><img src="https://images.theconversation.com/files/539908/original/file-20230728-23-ku5ia8.jpeg?ixlib=rb-1.1.0&rect=19%2C3%2C1274%2C857&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Photo by Stevie Ziogos</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Until the <a href="https://www.sciencedirect.com/science/article/pii/B9780081018729000042">late 19th century</a>, the success of criminal investigations largely hung on witness reports and (often extorted) confessions. A lack of scientific tools meant investigators needed advanced <a href="https://www.sciencedirect.com/topics/psychology/deductive-reasoning">deductive reasoning</a> abilities – and even then they’d often hit a dead end.</p>
<p>Today, investigations demand an interdisciplinary and <a href="https://link.springer.com/article/10.1007/s00414-022-02846-6">high-tech</a> approach, involving experts from diverse scientific disciplines. Stabbing investigations are particularly important, as fatal stabbings are the leading cause of homicide in countries with restricted access to firearms, including <a href="https://www.aic.gov.au/sites/default/files/2020-05/tbp045.pdf">Australia</a>.</p>
<p>Carefully interpreting <a href="https://theconversation.com/the-camera-never-lies-our-research-found-cctv-isnt-always-dependable-when-it-comes-to-murder-investigations-199828">CCTV footage</a> can be useful, but sometimes the crime scene won’t have surveillance cameras. The victim’s body may be discovered days, weeks, or months after the event. By then it may be partially consumed by insects – or rain may have washed away the blood stains, or potentially even the murder weapon.</p>
<p>In such a case, analysing damage to a <a href="https://www.ojp.gov/ncjrs/virtual-library/abstracts/comparing-alleged-weapon-damage-clothing-value-multiple-layers-and">victim’s clothing</a> can provide crucial insight. But how does clothing on a decomposing body react to environmental and biological factors?</p>
<p>This was our question as we conducted research using the decomposing bodies of more than 100 stillborn piglets. Our findings from this <a href="https://www.mdpi.com/2075-4450/14/7/618">first-of-its-kind experiment</a> could help investigators solve future (and past) crimes in which stabs, tears or other damages to clothing are in question.</p>
<h2>Pigs wrapped in fabric</h2>
<p><a href="https://www.sciencedirect.com/science/article/pii/S1355030618301680">Textile analysis</a> has a significant role in forensic investigation. Clothes can preserve crucial information about the events leading up to someone’s death. Evidence might come in the form of fibres under a victim’s fingernails, <a href="https://www.pnas.org/doi/10.1073/pnas.1917222117">tears in the clothing</a> resulting from movement or traction, or cuts and holes caused by weapons. </p>
<p>However, the decomposition process itself will also alter the fabric and existing damages. It may even introduce new damages that complicate the analysis.</p>
<p>To understand how clothing might change throughout this process, we conducted an experiment in the summer heat of Western Australia. We used more than 100 stillborn piglets (simulating human remains) wrapped in common fabrics including cotton, stretchy synthetic material, and a fabric blend. Some piglets were left unclothed as control samples.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/539902/original/file-20230728-25-grpb0x.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/539902/original/file-20230728-25-grpb0x.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/539902/original/file-20230728-25-grpb0x.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/539902/original/file-20230728-25-grpb0x.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/539902/original/file-20230728-25-grpb0x.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/539902/original/file-20230728-25-grpb0x.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/539902/original/file-20230728-25-grpb0x.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/539902/original/file-20230728-25-grpb0x.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The experiment was conducted at a facility in Western Australia.</span>
<span class="attribution"><a class="source" href="https://www.mdpi.com/2075-4450/14/7/618">Photo by Stevie Ziogos</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We intentionally inflicted cuts and tears on most of the fabrics, before leaving the carcasses to decompose naturally in a bushland environment until only bones remained. The bodies were shielded from <a href="https://pubmed.ncbi.nlm.nih.gov/20171028/">large scavengers</a>, but not from <a href="https://pubmed.ncbi.nlm.nih.gov/19836175/">carrion insects</a>. </p>
<p>While previous research has explored the impact <a href="https://pubmed.ncbi.nlm.nih.gov/21602003/">of clothing on decomposition</a>, we were focused on the other side of the coin: how do insects impact the fabric on a decomposing carcass? And in what ways could this jeopardise an investigation? </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/flies-maggots-and-methamphetamine-how-insects-can-reveal-drugs-and-poisons-at-crime-scenes-176981">Flies, maggots and methamphetamine: how insects can reveal drugs and poisons at crime scenes</a>
</strong>
</em>
</p>
<hr>
<h2>Exposed to natural elements</h2>
<p>It wasn’t long before the fabrics started to transform due to exposure to bacteria, fungi, insects and other environmental factors. </p>
<p>They changed in shape and texture, and became stretched as a result of the natural bloating of the carcasses. Less than a week after the carcasses were placed, new holes appeared in the fabric – especially in cotton – as the fibres broke down.</p>
<p>There were also chemical changes due to potential exposure to body fluids and the chemical products of bacteria and fungi.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/539897/original/file-20230728-27-48r2yd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/539897/original/file-20230728-27-48r2yd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/539897/original/file-20230728-27-48r2yd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/539897/original/file-20230728-27-48r2yd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/539897/original/file-20230728-27-48r2yd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/539897/original/file-20230728-27-48r2yd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/539897/original/file-20230728-27-48r2yd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/539897/original/file-20230728-27-48r2yd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Experimental fabrics observed with a ‘scanning electron microscope’ (SEM) showed fungal colonisation.</span>
<span class="attribution"><a class="source" href="https://www.mdpi.com/2075-4450/14/7/618">Photo by Stevie Ziogos</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Insects were particularly active in areas where body fluids were present. Of twenty insect groups collected and identified, blowflies and carrion beetles were the most common antagonists. </p>
<p>Throughout the 47 days of the experiment, we managed to collect a range of data on fabric degradation throughout the decomposition process. It’s the first time this has been documented in such detail in a controlled experiment. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/539893/original/file-20230728-19-9x88ao.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/539893/original/file-20230728-19-9x88ao.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/539893/original/file-20230728-19-9x88ao.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/539893/original/file-20230728-19-9x88ao.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/539893/original/file-20230728-19-9x88ao.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/539893/original/file-20230728-19-9x88ao.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/539893/original/file-20230728-19-9x88ao.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Insects visited the bloodstains of the fabric during the early stages of the experiment.</span>
<span class="attribution"><span class="source">Photo by Stevie Ziogos, Author provided</span></span>
</figcaption>
</figure>
<h2>New tools to solve new (and old) mysteries</h2>
<p>Although textile damage analysis is vital for forensics, there has been limited research on how it overlaps with forensic entomology and taphonomy (the study of how organisms decompose). Our research shows fabrics can hold significant evidence, and this evidence changes as bodies decompose while being exposed to the environment.</p>
<p>There are myriad examples of crimes where evidence related to clothing has been crucial to solving the case. </p>
<p>In the 1980 <a href="https://www.injustice.law/2021/07/05/the-shameful-tale-of-what-happened-to-lindy-chamberlain/">Chamberlain case</a>, a jury wrongly found Lindy Chamberlain and her husband Michael guilty of murdering their nine-week-old daughter Azaria, who had disappeared. </p>
<p>It was only when Azaria’s clothing was recovered a week after her disappearance that investigators had evidence of a dingo having snatched her (as the clothes showed signs of having been dragged through sand). The Chamberlains were exonerated as a result.</p>
<p>More recently, a person of interest was arrested in New York as the “<a href="https://7news.com.au/news/crime/architect-charged-over-murders-after-pizza-crust-leads-to-craigslist-ripper-breakthrough-c-11284691">Craigslist ripper</a>”, a serial killer responsible for the murder of more than ten people. Investigators obtained DNA evidence from strands of hair found in <a href="https://www.smh.com.au/world/hunt-for-ripper-as-new-york-beach-body-count-mounts-20111202-1obc7.html">burlap sacks</a> used to hide and transport the bodies. </p>
<p>Although many details of this particular case remain undisclosed, such investigations will most likely use insect-related evidence and other trace evidence on textiles to help make important inferences, including about time of death.</p>
<p>More generally, our work will help investigators avoid misinterpreting evidence from clothing. For instance, if investigators aren’t aware holes in fabric can form through exposure to insects and natural elements, they might incorrectly attribute them to an animal or human attacker. </p>
<p>Similarly, by gauging which portion of clothing has the most insect damage, they might be able to understand where the most fluid was present on the body (if it’s found as skeletal remains). This could help them figure out where and how damage was inflicted.</p>
<p>This year we published <a href="https://pubmed.ncbi.nlm.nih.gov/37367352/">guidelines</a> to help other forensic professionals in the process of observing and collecting insects at a crime scene, and in considering how insect activity may be connected with a victim’s clothing. We hope our work can help future investigations, and maybe even reopen some cold cases.</p><img src="https://counter.theconversation.com/content/207418/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>This research has been conducted in collaboration with Stevie Ziogos (PhD candidate, Murdoch University) and Kari Pitts (ChemCentre). Forensic entomology guidelines have been updated in collaboration with Tharindu Bambaradeniya (PhD candidate, Murdoch University).</span></em></p><p class="fine-print"><em><span>Ian Dadour does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Fatal stabbings are the leading cause of homicide in countries with restricted access to firearms, including Australia. New research could help solve these cases.Paola A. Magni, Senior Lecturer in Forensic Science, Murdoch UniversityIan Dadour, Adjunct professor, Murdoch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1769812022-02-28T19:14:05Z2022-02-28T19:14:05ZFlies, maggots and methamphetamine: how insects can reveal drugs and poisons at crime scenes<figure><img src="https://images.theconversation.com/files/448798/original/file-20220228-4024-xsiszf.jpeg?ixlib=rb-1.1.0&rect=0%2C0%2C2389%2C1580&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>The oldest book of zoology was <a href="https://en.wikipedia.org/wiki/Urra%3Dhubullu">published on clay tablets more than 3,600 years ago</a>, and reported the names of 396 types of wild animals known at the time. Ten of them were different kinds of fly. </p>
<p>Flies have lived alongside humans since the dawn of history, feeding on our bodily fluids and other organic waste such as meat and vegetable scraps. When an adult female blowfly finds some juicy decaying material – typically a carcass – she may lay hundreds of eggs or tiny maggots in it.</p>
<p>So flies use us, our products, our waste, and even the bodies of our dead. How can we use them in return?</p>
<p>One way is <a href="https://pubmed.ncbi.nlm.nih.gov/14991142/">the science of forensic entomology</a>. At a crime scene, flies and maggots can be used to determine how long it has been since a person or animal died, if they have been moved or neglected prior to death – and what drugs or poisons they had in their system.</p>
<h2>From flies on a sickle to modern forensics</h2>
<p>The first recorded instance of flies helping out in a murder case was during the 13th century. </p>
<p>A Chinese judge named <a href="https://en.wikipedia.org/wiki/Song_Ci">Sung T'zu</a> was sent to investigate a fatal stabbing in a rice field. </p>
<p>At the scene of the murder, he asked all the workers to lay down their sickles. After a short time, several flies swarmed on one of the sickles, attracted by the smell of invisible traces of blood. </p>
<p>Sung T'zu wrote about the case in <a href="https://www.jstor.org/stable/10.3998/mpub.19945">The Washing Away of Wrongs</a>, the oldest known book on forensic medicine, printed in 1247. He showed how thinking “outside the box” using clues from nature can help in forensic investigations. </p>
<p>It was several more centuries before the scientific method was applied to the use of flies in criminal investigations. The discipline of forensic entomology as we know it was not born until 1894, with the publication of <a href="https://collections.nlm.nih.gov/catalog/nlm:nlmuid-28421710R-bk">Carrion Fauna: The Application of Entomology to Legal Medicine</a>, by the French army veterinarian and entomologist Jean Pierre Mégnin.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/meet-the-maggot-how-this-flesh-loving-butt-breathing-marvel-helps-us-solve-murders-166518">Meet the maggot: how this flesh-loving, butt-breathing marvel helps us solve murders</a>
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<p>Since then, research on blowfly growth rates, decomposition patterns in different environments and use of blowflies to clean up the wounds (<a href="https://pubmed.ncbi.nlm.nih.gov/32825736/">debridement or “maggot” therapy</a>) have gained momentum. </p>
<p>Often flies can help estimate the time of death, as an entomologist can identify the flies or maggots, look at environmental conditions such as temperature, and thereby calculate the amount of time they have been growing.</p>
<p>Forensic entomologists are often involved at crime scenes, and <a href="https://pubmed.ncbi.nlm.nih.gov/9670502/">many suspicious deaths of humans and animals</a> have been solved with the help of insects. </p>
<h2>You are what you eat</h2>
<p>However, drugs and poisons can also affect how attractive blowflies find the carcass, and how quickly maggots grow on it. This means we often need to identify what drugs or poisons we are dealing with.</p>
<p>This can be found by analysing blood, urine, solid tissue or hairs from the dead body. But in some cases all that remains is a skeleton, so these are unavailable.</p>
<p>In these cases, we need to think outside the box, just like Sung T'zu. The old adage says “you are what you eat”, so insects feeding on a body should take in substances from the body and store them in their own bodies.</p>
<p>Furthermore, insects’ hard external skeleton is made of chitin, a comparable substance to the keratin protein from which hair is made. Similarly to hair keratin, insect chitin stores drugs for a long time, which is helpful for toxicological analyses. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/448804/original/file-20220228-23-ls9wc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/448804/original/file-20220228-23-ls9wc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/448804/original/file-20220228-23-ls9wc8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/448804/original/file-20220228-23-ls9wc8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/448804/original/file-20220228-23-ls9wc8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/448804/original/file-20220228-23-ls9wc8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/448804/original/file-20220228-23-ls9wc8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Insect exoskeletons are made of chitin, a substance that stores traces of drugs for a long time.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Insects collected from a carcass can be used as alternative toxicological specimens in situations where traditional sources are not available. Knowing the effect of the toxins on the life cycles of the flies can be used to adjust what we know about their growth rates.</p>
<p>In the early 1970s, the Finnish biologist Pekka Nuorteva showed <a href="https://www.jstor.org/stable/23731650">mercury from a fish carcass could transfer to carrion flies</a>. A few years later a similar analysis was used to determine whether a murder victim had lived in a polluted area. By 1977 the hybrid discipline of entomotoxicology (entomology + toxicology) became a reality. </p>
<p>When tissues and fluids are unavailable, insects are more reliable than hair to detect drug use just before death. They are also easier to analyse than decomposed matter. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/mummies-have-had-a-bad-wrap-its-time-for-a-reassessment-48729">Mummies have had a bad wrap – it's time for a reassessment</a>
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</em>
</p>
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<p>What’s more, they are available for a very long time. Empty fly puparial cases (cocoons left in the environment by the adult fly after its metamorphosis) as well as skin of carrion beetles have even been used for <a href="https://academic.oup.com/jme/article/52/5/755/831468?login=false">toxicological studies</a> of <a href="https://www.ojp.gov/ncjrs/virtual-library/abstracts/isolation-amitriptyline-and-nortriptyline-fly-puparia-phoridae-and">mummified bodies</a> found weeks, months, or even years after death. </p>
<p>And since <a href="https://www.sciencedirect.com/science/article/abs/pii/037907389390280N">cocaine has been detected in the hair of
3,000-year-old Peruvian mummies</a>, it might also be possible to detect drugs in the insects associated with ancient skeletal remains.</p>
<h2>Ice and antifreeze</h2>
<p>Since the beginning of the COVID-19 pandemic, there has been an <a href="https://www.commonwealthfund.org/blog/2022/overdose-deaths-surged-first-half-2021-underscoring-urgent-need-action">increase in drug overdose deaths</a> and also <a href="https://www.aaha.org/publications/newstat/articles/2020-07/big-spike-in-pandemic-related-pet-poisonings/">pet poisonings</a>. </p>
<p>My research group is developing ways to detect a range of drugs and other substances commonly found in the suspicious death of humans and animals.</p>
<p>One of these is <a href="https://pubmed.ncbi.nlm.nih.gov/24905151/">methamphetamine</a>, a large problem for Australian law enforcement and health authorities. Another is <a href="https://pubmed.ncbi.nlm.nih.gov/29753971/">ketamine</a>, a sedative and hallucinogen sometimes used to facilitate sexual assault. </p>
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<p>
<em>
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Read more:
<a href="https://theconversation.com/ice-age-the-rise-of-crystal-meth-in-australia-26052">Ice age: the rise of crystal meth in Australia</a>
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<p>We have also studied the effect of cheap, dangerous, and readily available poisons on blowflies, including</p>
<ul>
<li><p><a href="https://pubmed.ncbi.nlm.nih.gov/26874739/">nicotine</a>, which can be lethal if ingested from e-cigarette refills or if passed through the skin via nicotine patches</p></li>
<li><p><a href="https://pubmed.ncbi.nlm.nih.gov/29526269/">car antifreeze</a> (ethylene glycol), as it is sometimes used to make home-made alcoholic drinks or consumed by homeless people in winter in the hope to keep themselves warm at night</p></li>
<li><p><a href="https://academic.oup.com/jme/article/55/1/51/4344943">endosulfan</a>, a pesticide often used to make poison baits to kill animals.</p></li>
</ul>
<h2>More to be done</h2>
<p><a href="https://pubmed.ncbi.nlm.nih.gov/21237593/">Many compounds (such as drugs, metals and pesticides)</a> as well as <a href="https://pubmed.ncbi.nlm.nih.gov/28567525/">accelerants and gunshot residues</a> have been detected in insect tissues in a forensic context. However, fewer than 100 such studies have been carried out.</p>
<p>Furthermore, older research often lacks consistency, robust study protocols and method validations. Standard protocols and more sophisticated analytical methods can provide more accurate results that will hold more weight in court.</p><img src="https://counter.theconversation.com/content/176981/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paola A. Magni does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Forensic entomologists analyse blowflies and cocoon cases to help solve crimes.Paola A. Magni, Senior Lecturer in Forensic Science, Murdoch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1665182021-12-26T20:26:56Z2021-12-26T20:26:56ZMeet the maggot: how this flesh-loving, butt-breathing marvel helps us solve murders<figure><img src="https://images.theconversation.com/files/424020/original/file-20210930-26-1c3rcy0.JPG?ixlib=rb-1.1.0&rect=0%2C17%2C2379%2C2357&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Michelle Harvey</span>, <span class="license">Author provided</span></span></figcaption></figure><p><em><strong><a href="https://theconversation.com/au/topics/am-i-not-pretty-enough-106740">Am I not pretty enough?</a></strong> This article is part of The Conversation’s new series introducing you to Australia’s unloved animals that need our help.</em></p>
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<p>Not all superheroes wear capes – some live in rubbish bins, garbage dumps and on dead bodies. Maggots are the offspring of the blowfly, the scourge of the Aussie picnic, nuisance of summer and feared by farmers for infesting and killing sheep.</p>
<p>However, these humble little legless larvae are actually nature’s antibacterial soldiers. Their ability to survive and thrive in decomposing matter is making them our new secret weapon in forensic entomology – the science of using insects to solve crimes – and for cleaning chronic wounds.</p>
<p>But their success in this field depends on us seeing past the “yuck” factor and appreciating what these unique organisms can do for us. So what do maggots actually do, and why do we need them?</p>
<h2>Yes, they live in filth</h2>
<p>Maggots hatch from eggs laid by female blowflies on moist, microbe-rich matter. This might be a corpse, a wound, food waste or anything else palatable or decomposing. </p>
<p>After hatching, the maggots spread enzymes and bacteria that break down their food source into a delectable soup. They drink this soup, heads down and bottoms up, with their cleverly designed bottoms adapted for breathing. This means non-stop voracious feeding in this high nutrient, bacterially rich soup can continue uninterrupted – there’s no need to come up for air. </p>
<p>Their efficiency in recycling decomposing matter so rapidly and effectively makes them a fantastic waste disposal system, but their love of flesh is multi-faceted.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/429296/original/file-20211029-24-tp6xpu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/429296/original/file-20211029-24-tp6xpu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/429296/original/file-20211029-24-tp6xpu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429296/original/file-20211029-24-tp6xpu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429296/original/file-20211029-24-tp6xpu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429296/original/file-20211029-24-tp6xpu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429296/original/file-20211029-24-tp6xpu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429296/original/file-20211029-24-tp6xpu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Maggots cost Australian agriculture approximately A$173 million per year.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Let’s start with the negative. Attracted to all things decomposing, from rubbish to human remains, they live in filth. Bacterially infected environments are their happy place. </p>
<p>Unfortunately, this can extend to live animals, with wounds becoming infected by maggots, which is known as myiasis. The Australian sheep blowfly (<em>Lucilia cuprina</em>), for example, is responsible for flystrike on our sheep following the soiling of fleece with rain and body fluids. </p>
<p>It can result in significant discomfort and ultimately death for the animals. This costs Australian agriculture approximately <a href="https://www.wool.com/about-awi/media-resources/news/flystrike-vaccine-research-update-sep21/">A$173 million</a> per year .</p>
<h2>But there’s a flipside</h2>
<p>On the flipside, in forensic entomology we use the rapid attraction of female flies to lay eggs on human remains as a “biological clock”. </p>
<p>Flies are our detectives – moments after a person’s death decomposition begins, the odours produced from the remains quickly attract the flies. We determine the age of insects on remains to estimate the <a href="https://www.dovepress.com/entomology-based-methods-for-estimation-of-postmortem-interval-peer-reviewed-fulltext-article-RRFMS">time since death</a>.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/trust-me-im-an-expert-forensic-entomology-or-what-bugs-can-tell-police-about-when-someone-died-124416">Trust Me, I'm An Expert: forensic entomology, or what bugs can tell police about when someone died</a>
</strong>
</em>
</p>
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<p>Forensic entomologists have provided <a href="https://www.news.com.au/technology/science/animals/australias-weirdest-job-how-forensic-entomologists-use-insect-clues-to-assist-crime-investigations/news-story/7acb2a32763c801189b10a71584d2b49">valuable evidence</a> in many death investigations, and this is possible purely because blowflies are attracted to decomposing organic matter rich in bacteria.</p>
<p>Curiously, the bacteria don’t kill the insects and the larvae feed almost invincibly. This ability is being exploited in human health care. </p>
<p>The most intriguing interaction of maggots and humans is in an area known as maggot therapy. Clean, medical-grade maggots are intentionally and carefully introduced to a chronic wound, where they remove dead tissue and overcome the need for invasive surgical treatment. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/429298/original/file-20211029-19-1ak6367.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/429298/original/file-20211029-19-1ak6367.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/429298/original/file-20211029-19-1ak6367.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429298/original/file-20211029-19-1ak6367.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429298/original/file-20211029-19-1ak6367.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429298/original/file-20211029-19-1ak6367.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429298/original/file-20211029-19-1ak6367.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429298/original/file-20211029-19-1ak6367.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Maggots hatch from eggs laid by female blowflies.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p><a href="https://academic.oup.com/aesa/article/114/4/415/6207517">Research</a> has shown maggots don’t just remove the dead tissue by debriding the wound, they simultaneously kill off the harmful bacteria responsible for the infection. This occurs in the very acidic stomach of the maggot, as well as in the wound itself, where highly specialised antibacterial substances are excreted and secreted by the feeding larvae. </p>
<p>So maggots are not just eating machines to eliminate dead tissue, they are medicinal, utilising their own, bespoke pharmaceuticals to clean up wounds that often fail to respond to other treatment – and all for a bargain. A wound may be healed for approximately <a href="https://www.researchgate.net/publication/323738435_Maggot_medicine_in_Australia_2015">A$200-500</a> with no need for a hospital stay or surgical intervention. </p>
<h2>Why do they need more research?</h2>
<p>Chronic wounds are an increasing burden in the health system, with <a href="https://www.ama.com.au/media/patients-chronic-wounds-need-better-support">400,000 Australians</a> estimated to have a chronic wound or ulcer at any point in time. </p>
<p>This bears an estimated annual cost of <a href="https://www.mtaa.org.au/sites/default/files/uploaded-content/website-content/Chronic%20Woundsv5.pdf">A$2-4 billion</a> annually, with this figure likely to increase due to the ageing population and prevalence of chronic disease including diabetes. Additionally, antibiotic resistant “superbugs” are posing a challenge to effective wound treatment, which means surgery is needed where less invasive methods fail.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/429294/original/file-20211029-13-1kl81q3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/429294/original/file-20211029-13-1kl81q3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/429294/original/file-20211029-13-1kl81q3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429294/original/file-20211029-13-1kl81q3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429294/original/file-20211029-13-1kl81q3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429294/original/file-20211029-13-1kl81q3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429294/original/file-20211029-13-1kl81q3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429294/original/file-20211029-13-1kl81q3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Nature’s little superheroes are ready to help us, if only we let them.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>The importance of maggot therapy has been <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2600045/">recognised by some Aboriginal people, Central American Mayan tribes and wartime surgeons</a> in the 1500s and 1800s, but was abandoned in favour of antibiotics. </p>
<p>In the United Kingdom, maggot therapy is approved for doctors to prescribe and could save the National Health Service an estimated <a href="https://www.abc.net.au/worldtoday/content/2004/s1051346.htm">A$2.5 billion</a> per year. In the United States, maggot therapy has resurged and the US Food and Drug Agency provided clearance to market medicinal maggots in <a href="https://www.accessdata.fda.gov/cdrh_docs/pdf7/K072438.pdf">2004</a>. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/meet-the-penis-worm-dont-look-away-these-widespread-yet-understudied-sea-creatures-deserve-your-love-163728">Meet the penis worm: don't look away, these widespread yet understudied sea creatures deserve your love</a>
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</em>
</p>
<hr>
<p>In Australia, maggot therapy isn’t yet TGA approved, and we need to invest research dollars into understanding its mechanisms and conducting our own clinical trials before this will be achieved. </p>
<p>The maggots, while highly effective, are often misunderstood and clinical data is somewhat skewed by the fact maggots are always the last resort for a chronic, non-healing wound – right before amputation. </p>
<p>This life-saving service provided by the humble maggot all comes back to their love of bacteria and a good necrotic soup. So the next time you hose maggots out of your rubbish bin, pause to reconsider that “yuck” reaction, because nature’s little superheroes are ready to help, if only we let them.</p><img src="https://counter.theconversation.com/content/166518/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michelle Harvey does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Maggots are misunderstood, and we should see past the “yuck” factor and appreciate what these unique organisms can do for us.Michelle Harvey, Associate Professor, Deakin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1719592021-11-18T02:19:57Z2021-11-18T02:19:57ZHow do police forensic scientists investigate a case? A clandestine gravesite recovery expert explains<figure><img src="https://images.theconversation.com/files/432536/original/file-20211117-17-12mhnhc.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5729%2C3739&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Brendan Chapman</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Recent high-profile missing persons cases, including that of William Tyrrell – who went missing in Kendall, New South Wales, at the age of three in 2014 – have focused public attention on the forensic practices involved in crime scene investigations. </p>
<p>As a forensic scientist who has worked at thousands of homicide, sexual assault and serious crime scenes, I can tell you this process is not as straightforward as depicted on popular true crime shows.</p>
<p>I <a href="https://scholar.google.com.au/citations?user=RxkDXXAAAAAJ&hl=en">research</a> and teach <a href="https://www.murdoch.edu.au/thisisfreethinking/home">forensic science at Murdoch University</a> and specialise in <a href="https://www.murdoch.edu.au/news/articles/cold-case-review-at-murdoch">cold-case</a> techniques and clandestine gravesite recovery. Here’s what typically happens behind the lines of police tape when forensic teams are at work.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/this-is-going-to-affect-how-we-determine-time-since-death-how-studying-body-donors-in-the-bush-is-changing-forensic-science-117662">'This is going to affect how we determine time since death': how studying body donors in the bush is changing forensic science</a>
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<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/432534/original/file-20211117-17-a8pr7v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/432534/original/file-20211117-17-a8pr7v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/432534/original/file-20211117-17-a8pr7v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/432534/original/file-20211117-17-a8pr7v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/432534/original/file-20211117-17-a8pr7v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/432534/original/file-20211117-17-a8pr7v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/432534/original/file-20211117-17-a8pr7v.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/432534/original/file-20211117-17-a8pr7v.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The author teaches students clandestine grave site evidence collection techniques to Murdoch University students.</span>
<span class="attribution"><span class="source">Brendan Chapman</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>The crucial first moments</h2>
<p>In the first moments after a major crime, what has happened is often a mystery. </p>
<p>Like a scene from a painting, it’s as if time stood still; many regular household items sit as they did before the violent event took place. Investigators take great care not to disturb the initial scene, lest valuable evidence be lost.</p>
<p>The first task is to record everything as it appears in incredible detail – by video, photo and in written notes. Even items that may first appear innocuous can later take on new significance.</p>
<p>This stage is vital; years later, this may be the only way cold-case teams can virtually revisit the scene to identify new clues. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/432531/original/file-20211117-28-9dneev.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/432531/original/file-20211117-28-9dneev.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/432531/original/file-20211117-28-9dneev.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/432531/original/file-20211117-28-9dneev.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/432531/original/file-20211117-28-9dneev.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/432531/original/file-20211117-28-9dneev.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/432531/original/file-20211117-28-9dneev.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/432531/original/file-20211117-28-9dneev.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The first task, before anything in the scene is disturbed, is to record everything as it appears.</span>
<span class="attribution"><span class="source">Brendan Chapman</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Evidence testing and collection</h2>
<p>As the forensic investigation unfolds, information and evidence are gathered and given to investigators at the crime scene. This helps provide context to guide the search for evidence.</p>
<p>The crime scene team works meticulously to identify and “field-test” items (meaning tests are done in situ) before securing them in bags. </p>
<p>In some cases, that’s by using chemicals and testing kits to identify body fluids or other traces associated with the crime. </p>
<p>We also use some very high-tech torches that can emit a specific type to light to help us see otherwise invisible clues. This works a bit like the lighting in nightclubs that might expose lint on your black outfit.</p>
<p>At this stage, the best crime scene examiners invoke the scientific method, proposing <a href="https://wires.onlinelibrary.wiley.com/doi/10.1002/widm.1354">hypotheses</a> as to what has happened, and then searching for evidence that may refute their suggestion. </p>
<p>Theories are presented and then ruled out in place of new theories as new evidence emerges. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/432295/original/file-20211116-27-102xibz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/432295/original/file-20211116-27-102xibz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/432295/original/file-20211116-27-102xibz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/432295/original/file-20211116-27-102xibz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/432295/original/file-20211116-27-102xibz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/432295/original/file-20211116-27-102xibz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/432295/original/file-20211116-27-102xibz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/432295/original/file-20211116-27-102xibz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The crime scene team works meticulously to identify and field test items of evidence before securing them in bags.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Testing for traces of blood, semen and other body fluids</h2>
<p>On the scene, forensic investigators have a suite of tools to help identify body fluids such as semen and blood.</p>
<p>The <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2523691/?page=1">Kastle–Meyer test</a>, deployed to test for the possible presence of blood, has been used since the early 20th century.</p>
<p>A chemical called phenolophthalin is dropped onto the suspected sample, followed quickly by a drop of hydrogen peroxide. These chemicals can detect the blood ingredient haemoglobin. If it rapidly turns pink, there’s a good chance there’s blood in the sample.</p>
<p>A different method called the acid phosphatase test, which can detect an enzyme secreted from the prostate gland, is used to identify the presence of semen. A prepared chemical is dropped onto a sample of the suspected stain; a colour change from clear to dark purple suggests the likely presence of semen.</p>
<p>You may also have heard of investigators using <a href="https://www.abc.net.au/news/2021-11-17/william-tyrrell-investigation-technology-explained/100626684">luminol</a>, which can detect old blood stains or traces a person has tried to scrub away. The investigator sprays luminol and other chemicals on a darkened area; a blue glow suggests traces of blood may be present.</p>
<p>For all these tests, and everything we do as forensic investigators, meticulous records are kept about both observations and ideas. These notes will eventually become part of the huge case file that goes to court. </p>
<h2>Different types of forensic experts work together</h2>
<p>There are many different types of specialist crime scene investigators, such as:</p>
<ul>
<li><p><strong>fingerprint specialists</strong>, who use chemicals and powders to visualise fingerprints invisible to the naked eye and determine if they’re good enough to compare with prints on a database</p></li>
<li><p><strong>bloodstain pattern analysis experts</strong> who, like Dexter from the eponymous crime show, observe the shape of blood droplets or marks in an effort to reconstruct a bloodshed scenario</p></li>
<li><p><strong>physical evidence comparison experts</strong>, who record evidence such as shoe impressions or tool marks to compare with objects at the scene (for example, was <em>this</em> screwdriver used to create <em>that</em> mark on a window frame?)</p></li>
<li><p><strong>ballistics and firearms experts</strong>, who identify and analyse evidence such as gunshot residues and fired bullets. They can also reconstruct shooting events to determine trajectories and distances</p></li>
<li><p><strong>clandestine grave recovery experts</strong> (like me!), whose knowledge of the natural processes after death can help <a href="https://link.springer.com/article/10.1007/s11896-021-09457-8?wt_mc=Internal.Event.1.SEM.ArticleAuthorOnlineFirst&utm_source=ArticleAuthorOnlineFirst&utm_medium=email&utm_content=AA_en_06082018&ArticleAuthorOnlineFirst_20210521">locate and exhume grave sites</a> using painstakingly careful archaeological approaches. </p></li>
</ul>
<p>Other specialised forensic practitioners include pathologists, <a href="https://theconversation.com/trust-me-im-an-expert-forensic-entomology-or-what-bugs-can-tell-police-about-when-someone-died-124416">insect experts</a>, anthropologists, biologists and chemists. </p>
<p>Forensic investigations are most successful with a <a href="https://www.emerald.com/insight/content/doi/10.1108/JCP-09-2019-0038/full/html">multidisciplinary</a> team, which allows for many different opinions and ideas. </p>
<p>Specialists must work together to ensure one person’s evidence-collection method doesn’t ruin another specialist’s chance to use their own techniques.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/trust-me-im-an-expert-forensic-entomology-or-what-bugs-can-tell-police-about-when-someone-died-124416">Trust Me, I'm An Expert: forensic entomology, or what bugs can tell police about when someone died</a>
</strong>
</em>
</p>
<hr>
<h2>Clandestine gravesites</h2>
<p>Outdoor scenes present extra challenges, as evidence can be damaged or destroyed by weather, wildlife and the landscape itself. Clandestine gravesites, however, can help preserve clues underground.</p>
<p>It’s not easy to find a hidden burial site; even a freshly dug gravesite, if done well, can be difficult to identify in an expansive bush scene. </p>
<p>Investigators will be looking for areas where the ground looks disturbed or spots where vegetation has grown unusually lushly (caused by the decomposition of a body underneath).</p>
<p>Investigators may also deploy cadaver dogs to search for human remains, or <a href="https://www.abc.net.au/news/2021-11-17/william-tyrrell-investigation-technology-explained/100626684">ground-penetrating radar</a>, which uses radio waves to identify changes in the soil underground.</p>
<p>Once a grave is identified, you can’t just roughly dig it up; the grave fill must be gradually removed using small brushes and shovels, like those used on archaeological dig sites.</p>
<p>All removed soil is sifted and searched for tiny pieces of evidence; even a tiny fibre or hair could connect the grave to a suspect. </p>
<p>Even the sidewalls of the grave can offer clues about the type or shape of the shovel used to dig it. </p>
<p>Layer by layer, we work down until we reveal the deceased person at the bottom of the grave. Utmost care is taken here, as repatriation of the remains to loved ones is a pivotal part of the process of gaining closure.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/432533/original/file-20211117-23-qhvavi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/432533/original/file-20211117-23-qhvavi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/432533/original/file-20211117-23-qhvavi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/432533/original/file-20211117-23-qhvavi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/432533/original/file-20211117-23-qhvavi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/432533/original/file-20211117-23-qhvavi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/432533/original/file-20211117-23-qhvavi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/432533/original/file-20211117-23-qhvavi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It’s not easy to find a hidden burial site; even a freshly dug gravesite, if done well, can be very difficult to identify in an expansive bush scene.</span>
<span class="attribution"><span class="source">Brendan Chapman</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Time is of the essence</h2>
<p>All evidence has a life span. The sooner forensic scientists can identify and analyse a piece of evidence, the better the chances are of it producing a result. </p>
<p>This can be one of the greatest challenges in a cold case, where a crime scene has been changed by the elements over many years.</p><img src="https://counter.theconversation.com/content/171959/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brendan Chapman does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>As a forensic scientist who has worked at thousands of homicide, sexual assault and serious crime scenes, I can tell you the process is not as straightforward as depicted on popular true crime shows.Brendan Chapman, Senior Lecturer in Forensic Science, Murdoch UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1244162019-10-06T18:56:05Z2019-10-06T18:56:05ZTrust Me, I’m An Expert: forensic entomology, or what bugs can tell police about when someone died<figure><img src="https://images.theconversation.com/files/294699/original/file-20190930-185369-1jmihbw.jpg?ixlib=rb-1.1.0&rect=7%2C7%2C4980%2C3322&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Maggots are a major part of the puzzle when it comes to collecting forensic evidence. </span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>A few episodes ago, we <a href="https://theconversation.com/this-is-going-to-affect-how-we-determine-time-since-death-how-studying-body-donors-in-the-bush-is-changing-forensic-science-117662">heard from forensic scientists</a> at the Australian Facility for Taphonomic Experimental Research (AFTER) – that’s the official name for what, in books and movies, they would call a body farm. It’s there, at a secret bushland site, researchers are making some surprising discoveries about how donated human bodies decompose in Australian conditions.</p>
<p>One of the researchers there is Professor James Wallman, Head of the School of Life Sciences at the University of Technology Sydney, and one of the nation’s few forensic entomologists. </p>
<p>It’s his job to unpack little clues left behind by insects – including the much maligned blowfly – that can help police solve crimes when a body is found.</p>
<p>Today, James Wallman explains how and why insects have a really profound influence on decomposition. </p>
<p>We’re also re-broadcasting a clip from Maiken Ueland, the interim director of the AFTER facility, on how research underway there is changing what we thought we knew about determining time since death.</p>
<p>And if you’re interested in finding out more about how to donate your body for such research, you can start <a href="https://www.uts.edu.au/about/faculty-science/after-facility/body-donation">here</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/this-is-going-to-affect-how-we-determine-time-since-death-how-studying-body-donors-in-the-bush-is-changing-forensic-science-117662">'This is going to affect how we determine time since death': how studying body donors in the bush is changing forensic science</a>
</strong>
</em>
</p>
<hr>
<h2>New to podcasts?</h2>
<p>Podcasts are often best enjoyed using a podcast app. All iPhones come with the Apple Podcasts app already installed, or you may want to listen and subscribe on another app such as Pocket Casts (click <a href="https://pca.st/VTv7">here</a> to listen to Trust Me, I’m An Expert on Pocket Casts).</p>
<p>You can also hear us on Stitcher, Spotify or any of the apps below. Just pick a service from one of those listed below and click on the icon to find Trust Me, I’m An Expert.</p>
<p><a href="https://itunes.apple.com/au/podcast/trust-me-im-an-expert/id1290047736?mt=2&ign-mpt=uo%3D8"><img src="https://images.theconversation.com/files/233721/original/file-20180827-75984-1gfuvlr.png" alt="Listen on Apple Podcasts" width="268" height="68"></a> <a href="https://www.google.com/podcasts?feed=aHR0cHM6Ly90aGVjb252ZXJzYXRpb24uY29tL2F1L3BvZGNhc3RzL3RydXN0LW1lLXBvZGNhc3QucnNz"><img src="https://images.theconversation.com/files/233720/original/file-20180827-75978-3mdxcf.png" alt="" width="268" height="68"></a></p>
<p><a href="https://www.stitcher.com/podcast/the-conversation/trust-me-im-an-expert"><img src="https://images.theconversation.com/files/233716/original/file-20180827-75981-pdp50i.png" alt="Stitcher" width="300" height="88"></a> <a href="https://tunein.com/podcasts/News--Politics-Podcasts/Trust-Me-Im-An-Expert-p1035757/"><img src="https://images.theconversation.com/files/233723/original/file-20180827-75984-f0y2gb.png" alt="Listen on TuneIn" width="318" height="125"></a></p>
<p><a href="https://radiopublic.com/trust-me-im-an-expert-Wa3E5A"><img class="alignnone size-medium wp-image-152" src="https://images.theconversation.com/files/233717/original/file-20180827-75990-86y5tg.png?ixlib=rb-1.1.0&q=45&auto=format&w=268&fit=clip" alt="Listen on RadioPublic" width="268" height="87"></a> <a href="https://open.spotify.com/show/7myc7drbLJVaRitAMXLB7V"><img src="https://images.theconversation.com/files/237984/original/file-20180925-149976-1ks72uy.png?ixlib=rb-1.1.0&q=45&auto=format&w=268&fit=clip" width="268" height="82"></a> </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/trust-me-im-an-expert-what-science-says-about-how-to-lose-weight-and-whether-you-really-need-to-122635">Trust Me, I'm An Expert: what science says about how to lose weight and whether you really need to</a>
</strong>
</em>
</p>
<hr>
<p><strong>Additional audio</strong></p>
<p><em>Kindergarten by Unkle Ho, from <a href="https://www.elefanttraks.com/">Elefant Traks.</a></em></p>
<p><em><a href="https://freemusicarchive.org/music/David_Szesztay/20170730112627760/Backyard_1620">Backyard</a> by David Szesztay from Free Music Archive</em></p>
<h2>Images</h2>
<p><em>Shutterstock</em></p><img src="https://counter.theconversation.com/content/124416/count.gif" alt="The Conversation" width="1" height="1" />
James Wallman is one of Australia's few forensic entomologists. It’s his job to unpack the tiny clues left behind by insects that can help police solve crimes.Sunanda Creagh, Senior EditorLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1176622019-07-01T19:43:07Z2019-07-01T19:43:07Z‘This is going to affect how we determine time since death’: how studying body donors in the bush is changing forensic science<p>On the outskirts of Sydney, in a secret bushland location, lies what’s officially known as the <a href="https://www.uts.edu.au/about/faculty-science/after-facility/about-us">Australian Facility for Taphonomic Experimental Research</a> (AFTER). In books and movies, it’d be called a body farm. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/280632/original/file-20190621-149831-3k0kka.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/280632/original/file-20190621-149831-3k0kka.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/280632/original/file-20190621-149831-3k0kka.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/280632/original/file-20190621-149831-3k0kka.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/280632/original/file-20190621-149831-3k0kka.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/280632/original/file-20190621-149831-3k0kka.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/280632/original/file-20190621-149831-3k0kka.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/280632/original/file-20190621-149831-3k0kka.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Maiken Ueland at the AFTER facility run by UTS.</span>
<span class="attribution"><span class="source">Supplied by UTS</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Taphonomy is the study of how an organism breaks down after death. Research underway at the University of Technology Sydney’s AFTER facility is yielding some surprising new findings about how bodies decompose in the Australian bush.</p>
<p>And here’s an astonishing detail: until AFTER opened in Sydney in 2016, there was no facility like it in the southern hemisphere. Most of the world’s taphonomic research came from the US, meaning we were missing vital clues relating to how Australian weather, bugs and climate conditions affect the way a human body decomposes in the bush.</p>
<p>Today on our podcast, <a href="https://theconversation.com/au/podcasts/trust-me-podcast">Trust Me, I’m An Expert</a>, we take you on a journey to AFTER. The facility’s interim director, Maiken Ueland, and PhD student Samara Garrett-Rickman share with us:</p>
<ul>
<li>some of the unexpected findings emerging from AFTER on determining time since death;</li>
<li>why AFTER researchers prefer not to use the term “body farm”;</li>
<li>how the stages of decomposition work </li>
<li>a process of “mummification” that research suggests may be unique to Australian bushland conditions;</li>
<li>what the TV shows get wrong about forensic science; </li>
<li>why it’s harder to bury a body than most people think; </li>
<li>what investigators look for to spot a clandestine grave;</li>
</ul>
<p>And if you’re interested in finding out more about how to donate your body for such research, you can start <a href="https://www.uts.edu.au/about/faculty-science/after-facility/body-donation">here</a>. </p>
<h2>New to podcasts?</h2>
<p>Podcasts are often best enjoyed using a podcast app. All iPhones come with the Apple Podcasts app already installed, or you may want to listen and subscribe on another app such as Pocket Casts (click <a href="https://pca.st/VTv7">here</a> to listen to Trust Me, I’m An Expert on Pocket Casts).</p>
<p>You can also hear us on Stitcher, Spotify or any of the apps below. Just pick a service from one of those listed below and click on the icon to find Trust Me, I’m An Expert.</p>
<p><a href="https://itunes.apple.com/au/podcast/trust-me-im-an-expert/id1290047736?mt=2&ign-mpt=uo%3D8"><img src="https://images.theconversation.com/files/233721/original/file-20180827-75984-1gfuvlr.png" alt="Listen on Apple Podcasts" width="268" height="68"></a> <a href="https://www.google.com/podcasts?feed=aHR0cHM6Ly90aGVjb252ZXJzYXRpb24uY29tL2F1L3BvZGNhc3RzL3RydXN0LW1lLXBvZGNhc3QucnNz"><img src="https://images.theconversation.com/files/233720/original/file-20180827-75978-3mdxcf.png" alt="" width="268" height="68"></a></p>
<p><a href="https://www.stitcher.com/podcast/the-conversation/trust-me-im-an-expert"><img src="https://images.theconversation.com/files/233716/original/file-20180827-75981-pdp50i.png" alt="Stitcher" width="300" height="88"></a> <a href="https://tunein.com/podcasts/News--Politics-Podcasts/Trust-Me-Im-An-Expert-p1035757/"><img src="https://images.theconversation.com/files/233723/original/file-20180827-75984-f0y2gb.png" alt="Listen on TuneIn" width="318" height="125"></a></p>
<p><a href="https://radiopublic.com/trust-me-im-an-expert-Wa3E5A"><img class="alignnone size-medium wp-image-152" src="https://images.theconversation.com/files/233717/original/file-20180827-75990-86y5tg.png?ixlib=rb-1.1.0&q=45&auto=format&w=268&fit=clip" alt="Listen on RadioPublic" width="268" height="87"></a> <a href="https://open.spotify.com/show/7myc7drbLJVaRitAMXLB7V"><img src="https://images.theconversation.com/files/237984/original/file-20180925-149976-1ks72uy.png?ixlib=rb-1.1.0&q=45&auto=format&w=268&fit=clip" width="268" height="82"></a> </p>
<hr>
<h2>Additional audio</h2>
<p>Kindergarten by Unkle Ho, from <a href="https://www.elefanttraks.com/">Elefant Traks.</a></p>
<p>Backyard by <a href="http://freemusicarchive.org/music/David_Szesztay/20170730112627760/Backyard_1620">David Szesztay</a> from Free Music Archive</p>
<h2>Images</h2>
<p>UTS/Anna Zhu</p><img src="https://counter.theconversation.com/content/117662/count.gif" alt="The Conversation" width="1" height="1" />
On the outskirts of Sydney, in a secret bushland location, lies what's officially known as the Australian Facility for Taphonomic Experimental Research. In books or movies, it'd be called a body farm.Sunanda Creagh, Senior EditorLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1078652018-12-09T17:46:10Z2018-12-09T17:46:10ZHow the absence of blow flies overturned a wrongful conviction<figure><img src="https://images.theconversation.com/files/249163/original/file-20181206-186067-2j5rlb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Closeup of blow-fly or carrion fly Calliphoridae</span> <span class="attribution"><span class="source">corlaffra/Shutterstick.com</span></span></figcaption></figure><p>On Jan. 2, 2018, Kirstin Blaise Lobato, who was charged and convicted of murder, <a href="https://theintercept.com/2017/12/29/las-vegas-murder-kirstin-lobato-wrongful-conviction/">walked free</a> from a Nevada prison due entirely to forensic entomology. </p>
<p>Forensic entomologists study the insects colonizing a dead body to estimate how long they have been active on the body and infer time of death. What was so unusual in Lobato’s case was not the presence of insects, but rather the <em>absence</em> of insects on the body. </p>
<p>Yet neither defence nor prosecution lawyers queried this absence, an oversight that led to Lobato’s <a href="https://www.innocenceproject.org/kirstin-lobato-released-today-wrongly-serving-nearly-16-years-murder-didnt-commit/">16-year incarceration</a>. </p>
<p>It was only after I was contacted in 2009 to assess the <a href="https://www.sfu.ca/%7Eganderso/forensicentomology.htm">forensic entomology evidence</a>, or rather the lack of it, that it became clear there was forensic evidence that could prove her innocence.</p>
<h2>Violent, gruesome murder in Las Vegas</h2>
<p>Seventeen years earlier, at 10:15 p.m. on July 8, 2001, a homeless man was found brutally murdered in an outside trash area behind the Las Vegas strip. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/249174/original/file-20181206-186052-ojmjby.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/249174/original/file-20181206-186052-ojmjby.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=760&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249174/original/file-20181206-186052-ojmjby.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=760&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249174/original/file-20181206-186052-ojmjby.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=760&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249174/original/file-20181206-186052-ojmjby.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=955&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249174/original/file-20181206-186052-ojmjby.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=955&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249174/original/file-20181206-186052-ojmjby.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=955&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In this May 8, 2002, file photo, Kirstin Blaise Lobato awaits opening statements in her trial on charges of killing and sexual mutilation of a homeless man in Las Vegas in 2001. (AP)</span>
</figcaption>
</figure>
<p>He had been stabbed and slashed multiple times. His rectum had been cut open and his penis cut off. His body was found lying in pools of blood. </p>
<p>Lobato was identified as a suspect only because, a month earlier, a different man had attempted to rape her. She had defended herself with a small pocket knife and had slashed at her assailant’s genitals. She did not cut off his penis, but left him “crying.” </p>
<p>When police found that the dead man’s penis had been removed they searched for anyone in town who had cut a penis. They found Lobato, who was only 18 years old at the time, and charged her with the crime.</p>
<h2>Estimating time of death</h2>
<p>The pathologist originally stated that death had occurred just before the body was discovered at 10:15 p.m. Lobato had an unbreakable alibi for most of that day. However, the pathologist then changed his mind, determining death had occurred one to 12 hours before discovery. During the 2002 trial, he changed his opinion again — to as much as 24 hours before discovery. </p>
<p>Lobato was convicted of first-degree murder and sexual penetration of a dead body, despite any physical evidence tying her to the murder scene. </p>
<p>This trial, however, was overturned due to errors and Lobato was <a href="https://theintercept.com/2015/03/12/murderinvegas/">retried in 2006</a>, at which time the pathologist again changed his time of death and stated that the murder occurred eight to 14 hours before discovery. </p>
<p>This time, Lobato was found guilty of voluntary manslaughter and sexual penetration of a dead body. This latter charge was based on the rectum slashing, because it was claimed that this had occurred after death, despite the fact that pathologists stated it occurred while the victim was alive. </p>
<p>This is an important distinction because it resulted in Lobato’s registration as a sex offender for the rest of her life. </p>
<h2>No insect evidence was present</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/249171/original/file-20181206-186061-106rzz4.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/249171/original/file-20181206-186061-106rzz4.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/249171/original/file-20181206-186061-106rzz4.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=752&fit=crop&dpr=1 600w, https://images.theconversation.com/files/249171/original/file-20181206-186061-106rzz4.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=752&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/249171/original/file-20181206-186061-106rzz4.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=752&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/249171/original/file-20181206-186061-106rzz4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=944&fit=crop&dpr=1 754w, https://images.theconversation.com/files/249171/original/file-20181206-186061-106rzz4.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=944&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/249171/original/file-20181206-186061-106rzz4.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=944&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Kirstin Blaise Lobato’s Unreasonable Conviction, by Hans Sherrer.</span>
<span class="attribution"><a class="source" href="http://justicedenied.org/books/lobato_conviction_3rd.pdf">Justice Denied</a></span>
</figcaption>
</figure>
<p>In December 2009, Hans Sherrer, editor and publisher of <a href="http://justicedenied.org/"><em>Justice Denied</em></a>, a magazine dedicated to the wrongfully convicted, contacted me regarding Lobato’s case. He said he had photographs of the body and scene and asked if I could I do anything. </p>
<p>Normally, the answer to that is “no,” because a forensic entomologist cannot just “look” at a maggot. We need to study the insects under a microscope in order to see specific features. However, when Sherrer described the state of the body and the state’s case, <a href="https://vancouversun.com/news/local-news/sfu-profs-blowfly-evidence-clears-woman-imprisoned-16-years-for-murder">I agreed to take a look</a>.</p>
<p>Insects, in particular blow flies, are the first witnesses to a crime. They are attracted to a body <a href="https://www.crcpress.com/Carrion-Ecology-Evolution-and-Their-Applications/Benbow-Tomberlin-Tarone/p/book/9781138893849">immediately after death</a> if the conditions are appropriate. </p>
<p>They are attracted to lay their eggs close to wounds or orifices so that newly hatched <a href="https://www.amentsoc.org/insects/glossary/terms/instar">first instar</a> or first stage larvae can feed on liquid protein because, at this stage, they are unable to break an adult human’s dry skin. This means the female adults are very good at locating wound sites so their offspring can feed on blood.</p>
<p>Blow flies will lay large clumps of eggs on the body that are clearly visible; they look a bit like a small clump of grated Parmesan cheese. Even single eggs are one to two millimetres long, so they can easily be seen in a photograph. In this case, absolutely no insect evidence was present on the body.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/1Bn5Mp_TLV8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Innocence Project: Gail Anderson helps exonerate wrongly jailed U.S. woman.</span></figcaption>
</figure>
<h2>Blow flies indicate time of death</h2>
<p>Adult blow flies usually arrive within minutes, or even seconds, of death if conditions are appropriate, such as season, temperature, accessibility and time of day. </p>
<p>The insect season is generally from spring to fall in most of North America, so a death that occurs in mid-winter will not attract insects. Insects are cold-blooded, so their development and activities are governed by ambient temperature and they generally become inactive below around 10 to 12C. </p>
<p>They also need to be able to reach the corpse, so if it is well-wrapped in garbage bags or inside a house, they will be delayed. Finally, <a href="https://www.ncbi.nlm.nih.gov/pubmed/16423236">blow flies are diurnal</a>, which means they are active during the day and they rest at night. If a person dies in the night, they will not be colonized until the following morning.</p>
<p>In Lobato’s case, almost all circumstances were perfect for insect colonization: the season was summer, the weather was hot and the body was exposed outdoors with only a few pieces of trash covering him, which would not have impeded insects. The body was covered in wounds and very bloody so it would have been extremely attractive. </p>
<p>The only explanation for the lack of eggs on the body was that the victim died after sunset on the night his body was discovered. </p>
<h2>Determining death after sunset</h2>
<p>In December 2009, I submitted an affidavit stating that, in my opinion, the man had died after sunset on July 8, when Lobato had an air-tight alibi. </p>
<p>A writ of habeas corpus — indicating that Lobato was falsely imprisoned — was submitted in early 2010 but was denied in 2011. A reply brief was filed in October 2012, but there was no response until September 2014, almost two years later. A further two years elapsed before Lobato was granted a hearing in 2017 when the <a href="https://www.innocenceproject.org/">Innocence Project</a> became involved — an organization that works to exonerate the wrongfully committed. </p>
<p>I, and two other forensic entomologists whom I recommended, testified in front of a judge in October 2017. We all stated that insects would have been attracted to this body very rapidly and the lack of eggs suggested that death had occurred after sunset. Prosecution brought in a fourth entomologist who said you could not be absolutely sure. </p>
<p>Two months later the court granted Lobato’s writ of habeas corpus and ordered a new trial based on our evidence, stating that Lobato’s lawyers were ineffective in not consulting an entomologist in the original trial. </p>
<p>Ten days later, the court vacated Lobato’s conviction and dismissed all charges against her. Lobato was released “with prejudice,” meaning she cannot be retried.</p><img src="https://counter.theconversation.com/content/107865/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gail Anderson does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The presence of blow flies can help establish time of death in murder cases. A criminologist explains how she used her knowledge of blow flies to help overturn a wrongful conviction.Gail Anderson, Professor of Criminology, Undergraduate Director, Simon Fraser UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/417012015-05-13T05:17:53Z2015-05-13T05:17:53ZBacteria on shoes could help forensic teams catch suspects<p>Prospective criminals should take note: bacteria are everywhere. A <a href="http://dx.doi.org/10.1186/s40168-015-0082-9">small pilot study</a> has shown that the germs on personal belongings such as shoes and mobile phones are actually a useful way of tracing a person’s whereabouts – something that may prove useful in forensic investigations.</p>
<p>Microorganisms like bacteria are small, diverse and often specific to certain environments, organisms or individuals. This is also what makes them excellent as a forensic tool. In fact, like DNA and fingerprints, a suspect can unknowingly leave microbes behind on a crime scene or victim, providing useful information about the identity or origin of the suspect for <a href="https://theconversation.com/explainer-forensic-science-2817">forensic scientists</a>. One day, such microbial signatures of individuals may prove as important as DNA or fingerprints, although a lot more research is needed to get there.</p>
<h2>The age of bacteria</h2>
<p>Biology books typically state that we are living in the “age of mammals” that has followed the “age of dinosaurs” and the “age of the bacteria”. But, there are <a href="http://www.pnas.org/content/95/12/6578">loads more species of bacteria</a> than there are species of mammals. Looking at these numbers, along with the distribution and adaptability of the species, it seems we are still in the age of the bacteria. </p>
<p>Bacteria are the most abundant and genetically diverse organisms that we know. These germs ubiquitously inhabit the environment, including many extreme places like the glaciers in the high altitude, polar regions, or very hot thermal springs. Moreover, bacteria are present on different regions of the animal and human body, especially skin, mouth and the gastrointestinal tract. These body regions are home of diverse communities of bacteria and other microorganisms that can change <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3518434/">depending on the health status</a> and age of the host.</p>
<p>Several studies have been carried out <a href="http://hmpdacc.org/">to describe the human microbiome</a>, which is the collection of bacteria we are associated with, and to verify that the microbial signature can be used in the investigative field and, at the end of the legal process, in the court as proper evidence.</p>
<p>When arriving at a crime scene, the suspect usually has to walk. This was the starting point for the study, which tried to determine the possibility to trace people’s origin using the microbial community of their shoes. </p>
<p>This team looked at shoes from 89 participants randomly selected from attendees at three different scientific conferences in the US. They found that the shoes could be divided into three different groups according to the geographic locations of the conferences. This is because shoes that have travelled on different types of surfaces show distinct microbial signatures, in addition to a “core microbiome” belonging to an individual. This is obviously useful to forensic teams as it reveals the microbial signature of the owner as well as demonstrating where they have been before the sampling. </p>
<p>The team also showed that one of the most common objects that we use every day, the mobile phone, could also be of used in this way. They demonstrated that the pattern of microbes found on a telephone is unique. There are also differences between the front and the back since the back is mainly in contact with the hands and the front comes into contact with the face, and particularly with the mouth. These observations are supported by <a href="http://hmpdacc.org/health/projectdemos.php">previous studies</a> that demonstrated how different microbial communities are from different body parts – and that the personal microbial signature is unique. </p>
<h2>Hurdles to overcome</h2>
<p>However the authors also pointed to some difficulties in implementing the research. The microbiome on our soles typically changes throughout the day, which could make it hard to pinpoint the places we’ve been if we have walked around a lot. In the same way, the microbiome of a certain floor is also altered if a lot of people walk on it. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/81406/original/image-20150512-22568-che1pq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/81406/original/image-20150512-22568-che1pq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/81406/original/image-20150512-22568-che1pq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/81406/original/image-20150512-22568-che1pq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/81406/original/image-20150512-22568-che1pq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/81406/original/image-20150512-22568-che1pq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/81406/original/image-20150512-22568-che1pq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Cadaver-eating insects mapped.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/artmouse/11357100386/in/photolist-92k1q2-eRbtqA-baWLET-iiA7gC-8oKRDY">Danielle peña/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>But the microbiome could have other uses in forensics than locating suspects. In the past few years <a href="http://www.ncbi.nlm.nih.gov/pubmed/23749255">a lot of work has been done</a> in order to use the changes in the biome associated with decomposing bodies, called “necrobiome”, to estimate the time since death. The idea behind this approach follows what is already known and applied in another forensic discipline: <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3296382/">forensic entomology</a>. Insects, which colonise a cadaver in specific waves, are used in this field to give answers to one of the most crucial question on a homicide: when? This is because insects colonise a body in predictable waves, so the study of insects on cadavers tells us something about the minimum time since death.</p>
<p>The small study is important but will not be seen as a revolution by those working in forensics. It is simply the extension of “<a href="http://www.encyclopedia.com/doc/1G2-3448300354.html">Locard’s exchange principle</a>, one of the most robust pillars of the forensic work, to the microbial level: "Every contact leaves a trace”. More work is needed to determine the practical use of it in the future. A first step would be to scale up the experiment to include more people.</p><img src="https://counter.theconversation.com/content/41701/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stefano Vanin does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Germs on shoes and mobile phones are a good way of tracing criminal suspects, finds study.Stefano Vanin, Reader in Forensic Biology , University of HuddersfieldLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/20372011-08-16T20:41:37Z2011-08-16T20:41:37ZForensic entomology: the time of death is everything<figure><img src="https://images.theconversation.com/files/2713/original/3749947913_143d5508c6_b.jpg?ixlib=rb-1.1.0&rect=69%2C167%2C921%2C553&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Flesh-flies frequently give birth to maggots on corpses of human and other animals.</span> <span class="attribution"><span class="source">sankax</span></span></figcaption></figure><p>FORENSICS AUSTRALIA – Insects are everywhere. Their ubiquitous nature, and the fact they represent the largest biomass of animals on the earth, means there are hardly any terrestrial niches – except when an animal is buried, immersed in water or frozen – that have not been exploited by this group. </p>
<p>The main protagonist in insect attacks on cadavers is flies – two-winged insects and beetles. Most people experience flies – generally house flies and bush flies – while they are alive and consider them pests. </p>
<p>The flies that people see less of are blowflies, which tend to maintain a distance from animals until such animals are dead, comatose, unconscious or, in the case of some humans, heavily intoxicated. </p>
<p>There are some exceptions such as the <a href="http://www.flyboss.org.au/files/pages/susceptibility/blowfly-identification/B4_20_Blowfly_identification_NSW_DII_130410.pdf">sheep blowfly</a> and other <a href="http://www.medirabbit.com/EN/Skin_diseases/Parasitic/Myiasis/Miyasis_fly.htm">myiasis</a> flies that will strike a live animal.</p>
<p>Blowflies, depending on the species, either lay eggs or live larvae onto a corpse. This generally happens within an hour of the animal becoming immobile. </p>
<p>Blowflies are attracted to orifices, wounds and other moist locations such as between the fingers or toes, the armpits or any observable body crease. </p>
<p>When attending a crime scene it’s from these moist locations that insect material is sampled. </p>
<p>The insect material is then identified, sometimes based on the size of the immatures (maggots). The size of these immatures is a reflection of estimated age – the most important parameter by which minimum time of death can be estimated.</p>
<p>The person who does this work is a forensic entomologist. The term “forensic entomology” is generally used to describe the study of insects and other <a href="http://www.globio.org/glossopedia/article.aspx?art_id=15">arthropods</a> associated with certain suspected criminal events. </p>
<p>These typically include homicides, suspicious deaths, sudden deaths and suicides. </p>
<p>I have been involved with every aspect of forensic entomology for the past 23 years and am the only accredited forensic entomologist in Australia. </p>
<p>For ten years, I have also been part of the teaching faculty of the <a href="http://www.fbi.gov/knoxville/stories/12th-annual-human-remains-recovery-school">FBI’s Investigation Human Remains Recovery School</a>, teaching <a href="http://www.fbi.gov/about-us/lab/ert">Evidence Response Teams</a> for the last 10 years in the USA. </p>
<p>For me this has meant attending more than 200 homicides in Western Australia, Queensland, New South Wales and the Northern Territory, as well as reviewing cases in North America and Northern Ireland.</p>
<p>Of course, these numbers are low as Australia boasts one of the lowest homicide rates in the world (approximately one in every 100,000 people every year) and only 15-20% of these have any associated insect material present. </p>
<p>Estimating the minimum time of death sits within the broader discipline of medico-legal entomology which includes:</p>
<ul>
<li>determining the location of where a human death occurred</li>
<li>cases involving toxins, drugs and gunshot residues</li>
<li>the movement of vehicles and transport of remains</li>
<li>injuries after death</li>
<li>insect bites or infestations</li>
<li>neglect of the elderly</li>
<li>child abuse</li>
<li>food contamination by insects</li>
<li>veterinary and wildlife forensics. </li>
</ul>
<h2>Modern twists</h2>
<p>One traditional technique forensic entomologists have turned into a modern day treatment is maggot therapy. When antibiotics fail, many limbs have been saved by administering sterile maggots into gangrenous or necrotic wounds.</p>
<p>There are two other major areas where forensic entomology plays a role. </p>
<p>The first is urban entomology, which involves civil actions relating to insects and human-built structures, as may occur with termites and buildings. </p>
<p>This is becoming even more commonplace with the reduction into the environment of dangerous insecticides and no real protective barriers to insect attack. </p>
<p>The second is stored product entomology, which involves civil actions related to insect infestations of commodities such as food. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/2715/original/File_Calliphora_vomitoria_Portrait.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/2715/original/File_Calliphora_vomitoria_Portrait.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=467&fit=crop&dpr=1 600w, https://images.theconversation.com/files/2715/original/File_Calliphora_vomitoria_Portrait.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=467&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/2715/original/File_Calliphora_vomitoria_Portrait.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=467&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/2715/original/File_Calliphora_vomitoria_Portrait.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=587&fit=crop&dpr=1 754w, https://images.theconversation.com/files/2715/original/File_Calliphora_vomitoria_Portrait.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=587&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/2715/original/File_Calliphora_vomitoria_Portrait.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=587&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The blue bottle fly lays its eggs in decaying matter.</span>
</figcaption>
</figure>
<p>Have you ever unwrapped a muesli bar, opened a bag of fruit and nuts or checked a bag of flour on the shelf and found insects or webbing inside? </p>
<p>This is insect damage, which you can solve yourself by freezing such products for up to ten days following purchase to kill any insect material. </p>
<h2>Time flies</h2>
<p>The bread-and-butter reasons for forensic entomology involve ageing insects to determine a post-mortem interval (PMI). </p>
<p>With respect to time taken for carrion-eating insects to arrive on a body, there are many environmental and species-specific factors that will determine whether insects are common in the area of an unattended corpse. </p>
<p>In contrast, other types of insects will not be attracted by a corpse until it is in one of the later stages of decay. </p>
<p>So, the presence of an insect known to be attracted only by a dry, decayed corpse indicates that the corpse has been dead for some time and has already passed through fresh, bloat and wet decay stages. </p>
<p>And of course this is all dependent on weather factors, the most important being temperature and rainfall. </p>
<p>Insects (other than blowflies) that feed on decaying flesh include beetles, wasps and moths, and, by the time the last species arrives, the earliest arrivals are generally no longer present. </p>
<p>This is but a snapshot of what a forensic entomologist is expected to have expertise in, because as a result of any investigation involving insects, a “FE” will probably end up in a court of law to provide an opinion.</p>
<p>In essence, contemporary forensic entomology is a crucial tool in providing a chronological “gold standard” in the evaluation of postmortem intervals when insects are associated with a corpse.</p>
<p><strong><em>This is part three of The Conversation’s Forensics Australia series. Read <a href="http://theconversation.com/explainer-forensic-science-2817">part one</a> and <a href="http://theconversation.com/within-you-without-you-the-world-of-microbial-forensics-2284">part two</a>.</em></strong></p><img src="https://counter.theconversation.com/content/2037/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian Dadour receives funding from ARC and is affiliated with UWA</span></em></p>FORENSICS AUSTRALIA – Insects are everywhere. Their ubiquitous nature, and the fact they represent the largest biomass of animals on the earth, means there are hardly any terrestrial niches – except when…Ian Dadour, Director - Centre for Forensic Science, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.