In with a bullet (forensic bullet-tagging technology)

The Engineer ^ | 8/1/08

[LibWhacker]

A new bullet-tagging technology being developed in the UK could give forensic teams a robust new tool in the fight against gun crime.

The breakthrough has been achieved by a multidisciplinary team from Brighton, Brunel, Cranfield, Surrey and York universities, with funding from the Engineering and Physical Sciences Research Council (EPSRC). Project partners include the Forensic Science Service, BAE Systems and coatings manufacturer Andura.

The tags, which measure 30 microns in diameter, are applied to gun cartridges by being embedded in cartridge coatings made from polylactic acid, sucrose ester and tetrahydrofuran. They then attach themselves to the hands or gloves of anyone handling the cartridge and are said to be very difficult to wash off.

A portion of the tag remains on the cartridge even after it has been fired, which could make it possible to establish a definitive forensic link between a cartridge fired during a crime and whoever handled it.

The current success rates for DNA profiling using evidence from gun cartridges are only around 10 per cent. 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.

‘The tags primarily consist of naturally occurring pollen, a substance that evolution has provided with extraordinary adhesive properties,' said Prof Paul Sermon from Surrey University, who led the research.

He added: ‘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.’

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.

The technology has been designed to avoid damage to the DNA captured that is caused by temperatures generated as the gun is fired, when heat is rapidly transferred from the burning propellant into the cartridge case and when copper is extracted from the cartridge case by lactic acid in sweat.

The tag 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,’ said Prof 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.’

[SgtSki]

Aren't these the same guys that created the non nutritive cereal varnish?

[TC Rider]

I wonder how that stuff would hold up after a few hours in my brass tumbler with some ground walnut shells and a tablespoonful of Turtle Wax?

[Joe Brower]

"That's the point."

One of them, anyway.

[neverdem]

I'm surprised nobody posted this yet.

[longtermmemmory]

1. this was mentioned in a science digest or some such press release magazine.

2. this is being pushed by the company selling the technology. IOW there is no market for their product so they want to force the public to buy a product nobody wants.

[TigersEye]

They then attach themselves to the hands or gloves of anyone handling the cartridge and are said to be very difficult to wash off.

What if I load my gun with gloves months before I use it?

[TigersEye]

That was poorly stated. Let me rephrase before someone makes me eat that post. ;^)

"What if I load my gun with gloves on months before I use it?

[Myrddin]

Your alternative is as effective as theirs. Perhaps we should outlaw murder and prosecute people who aren't courteous enough to abide by that law.

[jdege]

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.

Didn't the FBI used to think that the precise composition of every batch of lead varied subtly from every other, and that could be used to enable a firm connection to be made between a specific bullet and the manufacturer's lot of which it was a part? Until, of course, someone tried to validate their "science", and discovered that the composition of lead varied subtly within each ingot, and there was significant overlap between ingots, such that there was as great a difference between different bullets that were part of the same lot as there were between lots.

[TXnMA]

"I’m sure there’s a dozen ways of defeating this if someone wants too."

Here's one:

[Redcloak]

The tags, which measure 30 microns in diameter, are applied to gun cartridges by being embedded in cartridge coatings made from polylactic acid, sucrose ester and tetrahydrofuran. They then attach themselves to the hands or gloves of anyone handling the cartridge and are said to be very difficult to wash off.

A portion of the tag remains on the cartridge even after it has been fired, which could make it possible to establish a definitive forensic link between a cartridge fired during a crime and whoever handled it.

The problem (more so in the US than in the UK) is that since firearms are ubiquitous, the tags themselves would soon become ubiquitous as well. Tags would show up at crime scenes even when no firearms were involved. They would be tracked over every square inch of a city like Los Angeles or New York. The technology would thus be rendered useless by the resulting low signal-to-noise ratio.

[Squantos]

Good lord !

That combination of chemicals aka polylactic acid, sucrose ester and tetrahydrofuran is together a toxic carcinogen that could kill someone ! < / sarcasm>

These silly games are just that ........such tag’s will just make bad guys wear gloves and good guys pay more for ammo that bad guys will steal.

Criminal wins again with seditious unconstitutional gun control.......as with ALL forms of gun control !

[from occupied ga]

lead and molds are common

But what if you prefer depleted uranium as a bullet material?

[calex59]

If you have access to it I don’t think I would talk about it! However, from what I hear the military does an excellent job with it.

[from occupied ga]

If you have access to it

I made no such claims, merely that I preferred it. :-) Tungsten (a distant second best choice) is readily available although rather expensive.

[calex59]

Yes, but tungston carbide is not depleted Uranium. :) I was just kidding with you anyway, some FReepers have a poor sense of humor.

[from occupied ga]

some FReepers have a poor sense of humor.

All too true. I was referring to tungsten metal as being better than lead, but not as good as DU (oh what a concidental name or maybe not. both are extremely dense), not tungsten carbide.