I’m always a big fan of stories that show science being used in real world examples that concern us all, so a newspiece on how researchers have found a new method of uncovering fingerprints on used bullet casings, is obviously very exciting to me.

Using fingerprints to identify people is clearly nothing new, according to wikipedia, even back in the 9th century it was used as a means of identification on loan agreements, although they were not used as a forensic tool until the late 19th century. But the various methods of extracting said fingerprints have been steadily improving through the years, and now there is one more for the CSI toolbox.

Researchers over at the University of Leicester, have been working with the Northamptonshire police department to create a new method to extract fingerprints from bullet casings that have already been fired. Any trace of an original fingerprint is usually destroyed when a bullet is fired, due to the extreme heat created, but what these guys did, was find out that the fingerprint corrodes the metal casing, and leaves a fingerprint etched into the metal, even after the original fingerprint has been obliterated by the heat.

The actual procedure of getting the fingerprint sounds quite simple. They apply an electric charge to the metal (bullet casing, or any metal really) that is coated in a very fine powder that can conduct electricity. The powder is then attracted to the etchings left by the criminals fingers, thus giving a fingerprint for them to test. So it sounds like it won’t require any crazy expensive equipment to work, so hopefully policemen can start putting it to good work without too much hassle.

Original press release.

Late addition:

I was done writing this article when i came across this webpage from Swansea University, which seems to suggest that this is not exactly a new concept. They even have pretty pictures and 3D visualizations of it all there (the picture in this article is from that experiment). From what i can tell though (and i may well be wrong), the method they are using at Swansea uses something called a Scanning Kelvin Probe, which appears to require much more expensive equipment then the method from the Leicester group do. So maybe THAT is the breakthrough, although that is not how i first interpreted their press-release.

I’m going to contact the guy that wrote this article (the original one i wrote about that is) and see what he has to say, so there might be a followup post in the next few days.