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Science behind condom-detecting fingerprint test explained: Dr Maartje van Angthoven

News was reported today on fingerprint technology which can detect the brand of hair gel used by a suspect or whether they have handled a condom, and could soon be used in court. Full story here.

The fingerprint test relies on mass spectrometry.

Dr Maartje van Angthoven is a researcher in the University of Warwick's Department of Chemistry - she explains how mass spectrometry works:

"Mass spectrometry is the technique of weighing molecules. To do that, you stick electric charges on the chemicals from a sample to turn them into ions. This process is called ionization. Some ionization methods can be used on chemicals directly on a surface. The ions can be sent through electric and magnetic fields. They move differently according to their mass and their charge, and you can measure their movements to find out their mass and their charge.

"Ions can also be bombarded with gas molecules, electrons, or light, in the mass spectrometer, in order to slow them down or break them up. These methods give more information on the shape and the structure of the chemicals that are being studied.

"When criminals leave a fingerprint behind at a crime scene, they do not only leave an important clue to their identity. They also leave behind a myriad of chemicals that reflect their lifestyle and the actions they took before and during the crime. The sweat making up a fingerprint contains chemicals coming from the food, drinks, medicines and drugs consumed before the crime, combined with residues from anything a criminal has touched.

"Dr. Simona Francese’s team has developed a method to ionize the chemicals from a fingerprint directly from a crime scene and to find out their chemical composition. The information from the test will give investigators more detailed forensic information in order to solve crimes."

10 October 2017

Further information contact:

Luke Walton, International Press Manager

+44 (0) 7824 540 863

+44 (0) 2476 150 868

L dot Walton dot 1 at warwick dot ac dot uk