Criminals beware - pollen could grass you up

Criminals who use firearms may find it much harder to evade justice in future, thanks to a new bullet tagging technology developed by scientists in the UK.

Pollen has extraordinary adhesive properties, it could even make a firearms charge stick in court

The tiny tags - just 30μm in diameter and invisible to the naked eye - are designed to be coated onto gun cartridges. They then attach themselves to the hands or gloves of anyone handling the cartridge and are very difficult to wash off completely. Crucially, some of these 'nanotags' also remain on the cartridge even after it has been fired. This should make it possible to establish a robust forensic link between a cartridge fired during a crime and whoever handled it.
“The tags primarily consist of naturally-occurring pollen, a substance that evolution has provided with extraordinary adhesive properties,” said Professor Paul Sermon from the University of Surrey, who has led the research. “It has been given a unique chemical signature by coating it with titanium oxide, zirconia, silica or a mixture of other oxides. The precise composition of this coating can be varied subtly from one batch of cartridges to another, enabling a firm connection to be made between a particular fired cartridge and its user.”   
To date it has been extremely hard to establish such a link because of the difficulty in retrieving fingerprints or significant amounts of DNA from cartridge surfaces, which are shiny and smooth.
In addition to this breakthrough, the team - consisting of chemists, engineers, sociologists and nanotechnologists from Brighton, Brunel, Cranfield, Surrey and York Universities - has also developed a method of trapping forensically-useful amounts of DNA on gun cartridges. It involves increasing the abrasive character of the cartridge case with micro-patterned pyramid textures, or adding an abrasive grit, held in place by a thin layer of resin, to the cartridge base.
“We’re currently focusing on understanding the precise requirements of the police and cartridge manufacturers,” comments Professor Sermon. “But our work clearly could make a valuable contribution not only to solving gun crime but also to deterring criminals from resorting to the use of firearms in the first place.”