Criminals who use firearms may find it much harder to evade justice in future, thanks to an ingenious new bullet tagging technology developed in the UK.
The tiny tags – just 30 microns* 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.
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. 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 funding from the Engineering and Physical Sciences Research Council (EPSRC).
"The tags primarily consist of naturally-occurring pollen, a substance that evolution has provided with extraordinary adhesive properties," says 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."
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. This rough surface is able to retain dead skin cells from a thumb as it loads a cartridge into a firearm. A key benefit is also the affordability – a cost-effective way of reliably capturing sufficient DNA from a gun cartridge has never been available before. The technology has been designed to avoid damage to the DNA captured which is caused (i) by temperatures generated as the gun is fired, when heat is rapidly transferred from the burning propellant into the cartridge case and (ii) when copper is extracted from the cartridge case by lactic acid in sweat.
The nanotag and DNA capture technologies could potentially be available for use within as little as 12 months. There may also be scope to apply them in other fields, such as knife crime, in future.
"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."
Notes for Editors
The 18-month 'DNA Receptors with Nanotags on Cartridges' initiative has consisted of two parallel projects receiving total EPSRC funding of nearly £379,000. Project partners are the Forensic Science Service, BAE Systems and coatings manufacturer Andura.
The original concept for the initiative was identified through the EPSRC Ideas Factory 'sandpit' process. A sandpit is a five-day interactive workshop involving a multidisciplinary mix of participants, some being active researchers and some being potential users of research outcomes, to drive lateral thinking and radical approaches to addressing particular research challenges.
Official Home Office statistics indicate that a total of 21,521 offences involving firearms were committed in England and Wales in 2005/06.
Current success rates for DNA profiling using evidence from gun cartridges are only around 10%.
Pollen from two types of lily, Lilium orientale and Lilium longiflorum, were used in this research.
The nanotags are applied to gun cartridges by being embedded in cartridge coatings made from polylactic acid, sucrose ester and tetrahydrofuran.
Nanotechnology involves manipulating materials on a very small scale.
* One micron is one millionth of a metre.
The Engineering and Physical Sciences Research Council (EPSRC) is the UK's main agency for funding research in engineering and the physical sciences. The EPSRC invests around £800 million a year in research and postgraduate training, to help the nation handle the next generation of technological change. The areas covered range from information technology to structural engineering, and mathematics to materials science. This research forms the basis for future economic development in the UK and improvements for everyone's health, lifestyle and culture. EPSRC also actively promotes public awareness of science and engineering. EPSRC works alongside other Research Councils with responsibility for other areas of research. The Research Councils work collectively on issues of common concern via Research Councils UK. Website address for more information on EPSRC: www.epsrc.ac.uk/
For more information, contact:
Professor Paul Sermon, Chemistry, Faculty of Health and Medical Sciences, University of Surrey, Tel: 01483 689593, E-mail: p.sermon@surrey.ac.uk
Three images (Tagged1.jpg, Tagged2.jpg and firingseqtable) are available from the EPSRC press office. Contact: Natasha Richardson, e-mail: natasha.richardson@epsrc.ac.uk, tel: 01793 444404.
Caption information:
'Tagged1.jpg' and 'Tagged2.jpg': "Tagged and bound: nanotags applied to cartridge cases and detectable, after firing, on the user's gloves".
'firingseqtable' (word doc): "The heat is on: infra-red reveals the high temperatures generated when a pistol fires a cartridge".