14 DAY TRIAL // Law enforcement officers have been relying on fingerprints lifted from crime scenes to catch bad guys for decades now. No two people have the exact same pattern of whirls, loops and archers on the tip of their fingers, so prints usually do a great job leading officers to law breakers.
The trouble is that, as popular as prints are when it comes to fighting crime, they can also complicate an investigation. This is because, at least for now, law enforcement officers can't tell just how old the marks they find at crime scenes are.
In turn, this makes it more difficult to rule out unnecessary suspects and instead only focus on the individuals who were at the crime scene at the time when the crime was committed.
“Law enforcement officials have long relied on fingerprints left behind by criminals to help solve cases. The ability to date fingerprints would allow police to more easily rule certain suspects in or out of their investigations,” EurekAlert explains.
There is a solution to this conundrum
In a new study published in the journal Analytical Chemistry, a publication of the American Chemical Society, a team of researchers propose that, contrary to popular opinion, the age of fingerprints can, in fact, be determined. All it takes is some good science.
The specialists explain that, when deposited, fingerprints have a very specific chemical composition. As they age, compounds begin to move around and their chemical profile changes ever so slightly.
For instance, a substance called palmitic acid tends to migrate away from print ridges. The migration happens at a steady and perfectly predictable rate, which means that, simply by looking at the distribution of palmitic acid in a print, its age can be established.
So far, scientists have used this method to accurately date fingerprints no older than 4 days. They are now trying to extend the dating interval to 10 days, maybe even include environmental variables.
