Almost 50% gun sales in the US take place outside the realm of background checks and other controls.
A US-based research group found that 40% of gun sales take place between unlicensed private parties, such as people buying and selling at gun shows. For sales that involve criminal intent the figure increases to above 80%.
The group recommended broadening the scope of background checks and creating a permanent record for guns purchased to limit gun-related violence and trafficking.
Read more at UC Davis Violence Prevention Research Program