GAITHERSBURG, Md., Aug. 12 (UPI) -- Crime investigators can use fingerprints to tell whether or not a person was at the scene, but they can't necessarily say when -- at least not from a fingerprint alone.
That could soon change, however. Researchers at the National Institute of Standards and Technology say they've developed a new technique for measuring the age of fingerprints.
The analysis could help forensic scientists put a time stamp on the bio signature, improving investigators' ability to identify the guilty parties and eliminate the innocent ones.
Scientists found that palmitic acid, a fatty acid found in humans, diffuses from the ridges of a fingerprint a predictable rate. By measuring the movement of the acid on a specific fingerprint, researchers say they determine how old the print is.
Currently, the method only works on fingerprints up to four days old, but scientists believe they will soon be able to expand that window to 10 days.
The technique's promise is detailed in a new paper published in the journal Analytical Chemistry.