BULLET tagging technology developed in the UK could help tackle gun crime.

The 'nanotags', made from pollen, would allow investigators to trace who has handled bullets used in a crime.

Invisible to the naked eye, the tiny tags could be coated onto gun cartridges and would then attach themselves to the hands or gloves of anyone who handled them. Some of the 'nanotag' would also remain on the cartridge after it has been fired, making it possible to establish a robust forensic link between cartridges fired during a crime and whoever handled them. 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 the shiny, smooth cartridge surfaces.

The technology could be available for use within a year and could also be used to combat knife crime. The nanotags, which are quite unlike anything previously used in the fight against gun crime, could therefore lead to a significant increase in successful convictions.

This breakthrough has been achieved by a team of chemists, engineers, management scientists, sociologists and nanotechnologists from Brighton, Brunel, Cranfield, Surrey and York Universities, with EPSRC funding.

Project partners are the Forensic Science Service, BAE Systems and coatings manufacturer Andura. Professor Paul Sermon from the University of Surrey, who has led the research, said: "The tags primarily consist of naturally-occurring pollen, a substance that evolution has provided with extraordinary adhesive properties.

"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."

In addition to this breakthrough, the team 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.

Professor Sermon added: "We're currently focusing on understanding the precise requirements of the police and cartridge manufacturers.