TV forensics
Forensic science has become a favourite of TV scriptwriters, with fictional criminals being caught through fingerprinting, fibre analysis and a toxicology report. What works for TV, however, doesn’t always play out in real life. For example, the success rate for DNA profiling of gun cartridges is currently around 10 per cent. This is why a team, with members from Brighton, Brunel, Cranfield, Surrey and York Universities, are working on a ‘bullet tagging’ technology.

‘We set ourselves a dual target of increasing the amount of DNA that was left on cartridge cases from the most recent people that have handled it,’ explains team leader Professor Paul Sermon from the University of Surrey. ‘Obviously, because some people wear gloves, you can’t guarantee the DNA will be left behind. The second of our dual targets was to ensure that there were tags on the surface of the cartridge case which was handled and left at the crime scene, this would then donate tags to the users skin, gloves and clothes.’

Lily flower
These nanotags, which are applied to bullets in a special coating, are 30 microns in diameter (one micron is one millionth of a metre). Not only are they invisible, but the tags are incredibly adhesive. Professor Sermon also explains that the structure of the tags is based on an old favourite of forensic  scientists – pollen. Their research was done with the lily flower, lilium longiflorum. ‘It has a nice unique morphology and structure, it’s resilient and really very stable at high temperatures.’ This is useful with the heat generated when a gun is fired.