Could your favorite jeans help catch your murderer?
If it’s true, we would then have favorite jeans posthumously. Would that be too cool or simply bizarre? Either way, it may soon be true! Scottish researchers are looking at ways to recover “fingerprint ridge detail and impressions from fabrics”. Doing so has been an elusive goal and the success has come with a technique called vacuum metal deposition (VMD). Basically, gold and zinc is used to recover the fingerprint mark.
Joanna Fraser, a forensic sciences researcher at the University of Abertay, Dundee, said: “The research uses fine layers of metals to display fingerprints people may have left on fabrics, something which is far harder to do with soft surfaces. The technique has been around since the 1970s and is used on many surfaces but was never widely used on fabrics.
“We take these fabrics, place them in a vacuum chamber, then heat up gold to evaporate it and spread a fine film over the fabric. We then heat up zinc, which attaches to the gold where there are no fingerprint residues. This helps reveal the fingerprint — where contact has been made we see the original fabric, where there was no contact we’re left with the grey colour of the metal film.”
She added: “One way of explaining it is like a photographic negative, where colours show up as their opposites. Here the fingerprint ridges show through as clear fabric, but where there are no ridges we see the distinctive grey colour of the metal.
“Previously it had proved difficult to reveal a clear fingerprint on fabric, but we’ve shown that this is now possible. This is great, but the challenge is to develop this further and confirm its effectiveness.”
So, for example, if your favorite jeans had two handprints on the butt—maybe you were shoved off the balcony as opposed to jumping. Or—if scientists find handprints or fingerprints on your favorite jeans—they know to target those areas for further DNA evidence.
There is nothing like a good pair of jeans. Overall, though, I can’t say I’m going to sleep better for knowing this.
Fraser J, Sturrock K, Deacon P, Bleay S, & Bremner DH (2010). Visualisation of fingermarks and grab impressions on fabrics. Part 1: Gold/zinc vacuum metal deposition. Forensic science international PMID: 21126838