Fingerprint Residues Can
Reveal Their Age
Monday, January 27, 2020
proof-of-concept study that uses a highly sensitive mass spectrometry method to
date fingerprints has its authors thinking they can test the promising methods
in real criminal cases within the next few years.
preliminary new study published in Analytical Chemistry, researchers Paige Hinners, Madison
Thomas and Young-Jin Lee from Iowa State University report they can link
compounds contained in fingerprints with their age. While crime lab scientists
have relied on fingerprints for over a century, pinning down the time the
fingerprint was left has proven difficult. Knowing the age of a fingerprint can
help investigators establish a better timeline, including ruling out a suspect
or contradicting a suspect’s story.
prints collected from three donors, the researchers tracked shifting levels of
triacylglycerols using matrix-assisted laser/desorption ionization mass
compounds in fingerprint can be measured with this technique but we focused on
triacylglycerols (body oil) as they are highly abundant and much more reliably
measured than others,” Lee told Forensic.
MALDI-MS results indicated the researchers could reliably determine the
triacylglycerol degradation rate for each person over the course of seven days.
But the rate differed among individuals, with one person’s triacylglycerols
declining more gradually than the others. The researchers attribute this
difference to higher levels of lipids in that individual’s fingerprints. The
method also worked on residues that had been dusted with forensic powder.
ozonolysis of fingerprint triacylglycerols has been recently shown by others,
but it is the first time to show that it can be used to reliably measure the
relative change of fingerprint composition over the first few days of
deposition,” Lee said.
“This publication is still a proof-of-concept experiment, although very promising,” Lee said. “We just got new funding from the forensic program of the National Institute of Justice. We will continue to thoroughly study the fingerprint aging for multiple variables, such as environmental effect, individual differences, and experimental conditions.”