New Technique Takes Fingerprint Analysis to a Whole New Level

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If you're a crime scene investigator, you'll definitely be searching for fingerprints. But as great as fingerprint technology is for catching bad guys (and providing fuel for tons of crime shows), it can't tell us important chemical information about that fingerprint, such as DNA or whether the person had recently come into contact with explosives. That is, until now.

The infrared laser in Murray's lab used to ablate fingermarks. Here, the laser is being channeled through an optical fiber.

A Simple System called Infrared Laser Ablation

Currently, crime scene investigators often take photos of fingerprints, then take swabs of the fingerprints to take back to labs for chemical evidence. But chemists at Louisiana State University have developed a new technology that could help identify chemical compounds in fingerprints at the actual crime scene. Their work is published in the Journal of the American Society of Mass Spectrometry.

It works like this: lasers scan fingerprints on a surface, heating them up and focusing a high amount of energy in a small area. With enough heat, chemical bonds in water stretch and eventually "explode," lifting up chemical compounds in the process (a process called laser ablation). Those compounds are then sucked into a filter, where they are analyzed using spectrometry techniques, a press release on the study explains. The technology could analyze a number of different compounds, including lipids, proteins, genetic material, or explosives, the press release says.

LSU researchers Fabrizio Donnarumma and Fan Cao set up an infrared laser system used to remove fingermark materials from a surface for chemical analysis.
Fabrizio demonstrates a flexible germanium oxide optical fiber laser attachment that could enable a portable fingermark ablation device for use by forensic experts. The laser light is visible as a red dot on the detection device.

New Tools for Solving Crimes

The new technology could have a major impact on solving crimes. Researchers can identify compounds (even the extremely delicate DNA molecule) at the scene of a crime. And in the future, the technology could also help bomb squads find and deactivate bombs without venturing into dangerous areas. They'll also be able to identify any genetic material present.

So far, the technology has been able to detect trace levels of caffeine, antiseptic cream, explosives, and more. Researchers are currently working on developing the technology before it hits the market.

Watch And Learn: Our Favorite Content About Fingerprinting

How does DNA fingerprinting work?

Key Facts In This Video

  1. People who are related to one another have similar VNTRs—Variable Number Tandem Repeats—in their DNA. 00:55

  2. DNA fingerprinting was commercialized in 1987. 02:30

  3. DNA fingerprinting is used in police forensics, paternity testing, immigration disputes, and even wildlife conservation. 04:22

Why Are Fingerprints Unique?

Key Facts In This Video

  1. Fingerprints don't change as we age. 00:13

  2. A random combination of stem cells create our unique prints. 00:48

Written by Stephanie Bucklin July 1, 2017

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