Explainer: how to solve a jewel heist (and why it takes so long)

Scene of the crime. Metropolitan Police/PA

The Hatton Garden heist was a burglary that to all intents and purposes appeared to be taken from a work of fiction. A daring raid that involved climbing down lift shafts, drilling through a reinforced concrete wall, gaining entry to a secure vault and breaking numerous secure metal safe boxes before making away with valuables, right under the noses of security and police.

The Metropolitan Police has come under some considerable pressure in this investigation, not least because it allegedly didn’t investigate an alarm activated at the premises. But now the investigation seems to have moved from snail’s pace over the Easter period, to making several charges in 48 hours. So what goes on and why is it all so slow?

Unfortunately, as members of the public, we are fed a diet rich in fictional crime investigations that are done and dusted within a matter of hours. People are so used to having things communicated, answered and solved almost instantly in this technological age that it is hard to comprehend why, with vast improvements in technology and know-how, real criminal investigations are not following suit.

The answer is that justice is a slow beast. Time and care need to be taken to ensure each and every i is dotted and t is crossed before a case can even get to court. Our justice system is hundreds of years old and the police have to work within the confines of laws, which may themselves be centuries old. The Police and Criminal Evidence Act 1984 gives the police the powers of search and arrest and also covers questioning and court proceedings. It is a lengthy document and just understanding the finer details of this would make most people appreciate why processes take so long.

Assembling the evidence

In the Hatton Garden enquiry the police would have needed a team of crime scene examiners to begin the painstaking process of recording the scene and searching and locating evidence, which will not just match to suspects but also help prove the offence. This evidence must be fully documented, as it may end up in court where a judge and jury will need to understand where it is from and how it relates to the crime and to the suspects.

CSI: Holborn. Andy Rain/EPA

The evidence is not just forensic, as in DNA and fingerprints, there is the circumstantial and intelligence evidence which the investigators have to collect from witnesses. This is in the form of statements, and hours of CCTV footage collected from varying locations and examined – and each piece of this evidence has the ability to link to other people and cameras (for example from the road network to follow the van). Each of these needs to be examined by an expert in the field under the constraints of the law.

An appointed senior investigating officer has the job of piecing each of the bits of the jigsaw together with a team and at each point there will be more tasks created for that team to follow up to ensure as much information is gathered before even considering an arrest strategy.

Making the arrest

In this case the arrests need warrants, which have to be granted by the Magistrates Court, in order to search each suspect’s home, work and vehicles. Each of these searches must be undertaken under constraints of the Police and Criminal Evidence Act, dictating how searches are managed and how long persons can be held in custody before being charged.

As the suspects are being interviewed, the investigating teams will be liaising with crime scene examiners who will be working at the various sites relating to suspects. Scientists and other experts will be examining some of the evidence and officers will be conducting further interviews with other people close to the suspects. Samples from the suspects will also be collected to check against evidence from the scene, including DNA and fingerprints.

Once the investigating officer is satisfied there is enough evidence, then a suspect is formally charged and in these types of cases they are usually remanded in custody rather than bailed. The work for the police won’t end there, as they begin to look at possible defence propositions and confirm that their case is strong enough to go to the Crown Prosecution Service.

In this crime, as in many, it really is like the tortoise and the hare – slow and steady is best. It may be frustrating for those who like their answers quick, but it’s absolutely necessary in terms of the law.