New Forensic Discovery: How Hidden Details in Your Fingerprints Could Solve More Crimes

A recent scientific discovery has reset the stage on what fingerprint reveals in criminal activities. Powerful new technology known as Desorption Electrospray Ionization Mass Spectrometry, or DESI-MS, has made it so that the forensic scientists are able to dig even deeper, finding not only people in hard or faint fingerprints but also gaining chemical information on what a person may have done recently, what drugs he or she may have used, what possible medical conditions they may have; age, sex, and even ethnicities.

What is DESI-MS?

DESI-MS is a state-of-the-art tool that enables investigators to analyze both the patterns and material composition of fingerprints left at crime scenes. This is how it is done:

• The finger is pressed to the surface and a gelatin lifter (which may already be in use in Indian forensic labs) is applied to gather the fingerprint.
• The lifter is sprayed with moderate intensity, electrically charged solvent mist (such as methanol).
• The chemical marks left in the fingerprint ridges are taken up by the mist.
• These chemicals are then analyzed in the DESI-MS, which gives both a picture of the fingerprint, and a breakdown of the chemicals in it.

Such technique is non-destructive, quick and able to retrieve spatial chemical information on prints that overlap, or in degraded prints, which could never have been imaged separately in the past with standard imaging.

Key Facts of the Recent Surveys

• With DESI-MS, the Aarhus University and other scientists were able to distinguish and identify overlapping fingerprints, even smudged or weak fingerprints, a first in reality in crime scenes.
• The technology enables discovery of drugs, medicines, explosive or even environmental chemicals which have been handled by an individual- essential information in establishing connections between people and crime scenes and activities.
• Machine learning with DESI-MS has been able to classify gender correctly (to 96%), age (84%), and ethnicity (82%), based on the individualized chemical profile in a fingerprint.
• DESI-MS is non-destructive and suitable for quick, in-situ analysis. In many cases, useful results are available within two hours. 

 What Information Can Now be  Extracted from Fingerprints? 

• Identification of the individual by the traditional ridge pattern and advanced chemical profiling.
• Detection of foreign substances by knowing whether the person recently touched drugs, explosives, lubricants, cleaning agents, or food remains.
• Personal profiling like gender, age range, ethnicity, and even possible health information, such as biomarkers for diseases.
• Newer studies have shown potential for DESI-MS to estimate when a fingerprint was deposited.

Indian crime scenes are full of overlapping and poor fingerprints which in the old times were usually treated as unacceptable evidence. Through DESI-MS, additional prints at the crime scene would be more usable, which can:

1. Assist in the solution of cold cases; i.e. older cases that remain unsolved.
2. With new chemical evidence, cause or eliminate wrongful convictions by including or eliminating suspects.
3. Serve investigative clues to cases related to narcotics or terrorism or environmental crimes.

Moreover, the technique can be integrated into the current workflow as gelatin lifters necessary in the processes are generally already in use by most labs; the transition toward DESI-MS may be cost-effective in comparison to replacing forensic protocols.

Future Difficulties and the Way Forwards

Although research shows that DESI-MS can be effective, extensive use will be at a cost of investment in equipment and training forensic teams in India. Judges and law enforcers should be sensitized about the process of gathering the chemical fingerprint testimony, its interpretation, and its manner of presentation before the court of law. Current research is extending the classes of chemicals that can be detected in fingerprints- future improvements may further individualize personal, medical, and behavioral profiling.

The innovation drives fingerprint evidence into the digital age. With the help of such tools as DESI-MS, each fingerprint can now reveal a much more detailed story not only about a person who left it but also about actions and things touched by the owner. That will translate to expedited case clearing and reduced trial errors, and lower costs among investigators as well as the justice system of India that has limited time and resources at their defense.

Tip: To read the original study or look at how such technology is being developed, see ScienceDaily coverage or search DESI-MS fingerprint for detailed research papers