0
0
September 14, 2024 – In a groundbreaking development for forensic science, researchers at the Department of Forensic Medicine at Aarhus University have unveiled a revolutionary method for fingerprint analysis that could significantly advance criminal investigations. This new technique, which leverages chemical imaging on gelatin lifters, promises to extract a wealth of information from fingerprints that was previously unattainable.
Traditionally, Danish police and forensic teams use gelatin lifters to collect fingerprints from delicate surfaces and irregular objects. These lifters are particularly valuable for capturing prints from challenging surfaces like peeling wall paint or door handles. However, once collected, the fingerprints are typically photographed and processed through databases. This conventional method often falls short when dealing with overlapping prints or faint impressions, leading to the discard of potentially crucial evidence.
The breakthrough, detailed in a recent study published in Analytical Chemistry, introduces a method based on Desorption Electrospray Ionization Mass Spectrometry (DESI-MS). This technique involves applying a fine spray of electrically charged methanol droplets to the fingerprint, which releases and ionizes the substances on the gelatin lifter. The resulting chemical compounds are then measured individually by their mass, providing a detailed chemical profile of the fingerprint.
Dr. Kim Frisch, a postdoc leading the study, explains, “Our method could seamlessly integrate into existing forensic workflows, allowing for more fingerprints to be analyzed and evaluated both visually and chemically. DESI-MS has shown potential beyond traditional optical imaging, revealing overlapping prints and enhancing faint ones that are otherwise challenging to process.”
While DESI-MS was originally developed for general surface analysis and had been used for fingerprints on glass and tape, this is the first time it has been applied to fingerprints on gelatin lifters. The researchers have already tested the method in laboratory settings and are now applying it to real-world crime scene evidence provided by the National Special Crime Unit of the Danish Police.
One of the most exciting aspects of this new method is its potential to offer deeper insights into the individuals who left the fingerprints. Beyond revealing the unique patterns, fingerprints contain a myriad of chemical compounds such as lipids, amino acids, and potential contaminants like nicotine, caffeine, or drugs. Future applications of this technique might enable forensic experts to profile suspects based on factors such as their diet, medication use, and even lifestyle choices.
The Department of Forensic Medicine is focusing on practical applications of this method, working closely with the Danish Police to ensure its effective integration into forensic investigations. While the process is currently time-consuming and not yet scalable to large volumes of samples, it holds promise for more complex cases, including serious crimes such as murder and rape.
Dr. Frisch concludes, “Our goal is to enhance forensic capabilities and provide law enforcement with more tools to solve crimes. As the technology develops, we anticipate it will become a valuable asset in the fight against crime.”
The research, supported by the Danish Victims Fund and ongoing for over two years, continues to explore how fingerprints can be used to gather detailed information about suspects, potentially transforming the landscape of forensic science and criminal investigation.
