A single fingerprint left at a crime scene could now be used to determine whether someone has ingested or handled class A drugs, including cocaine.

In a paper published in Royal Society of Chemistry’s Analyst journal, a team of researchers at the University of Surrey, in collaboration with the National Centre of Excellence in Mass Spectrometry Imaging at the National Physical Laboratory (NPL) and Ionoptika, reveal how they have been able to identify differences between fingerprints of people who ingested or touched cocaine.

The smart science behind the advance is the mass spectrometry imaging tools applied to the detection of cocaine and its metabolites in fingerprints. This is a step up from research previously conducted by the University. In 2020 Surrey researchers were able to determine the difference between touch and ingestion if someone had washed their hands prior to giving a sample. Given that a suspect at a crime scene is unlikely to wash their hands before leaving fingerprints, these new findings are a significant advantage to crime forensics.

The Surrey team has continued to use their world-leading experimental fingerprint drug testing approach based on high resolution mass spectrometry. Cocaine and its primary metabolite – benzoylecgonine, can be imaged in fingerprints produced after either ingestion or contact with cocaine using these techniques. By analysing the images of cocaine and its metabolite in a fingerprint, and exploring the relationship between these molecules and the fingerprint ridges, it is possible to tell the difference between a person who has ingested a drug, and someone who has only touched it.

“Over the decades, fingerprinting technology has provided forensics with a great deal of information about gender and medication,” said Dr. Melanie Bailey, from the University of Surrey. “These new findings will inform forensics further when it comes to determining the use of class A drugs.

“In forensic science being able to understand more about the circumstances under which a fingerprint was deposited at a crime scene is important. This gives us the opportunity to reconstruct more detailed information from crime scenes in the future. The new research demonstrates that this is possible for the first time using high resolution mass spectrometry techniques.”

According to Dr Allen Bellew at Ionoptika, imaging these metabolites excreted through the skin requires very powerful analytical tools, such as the unique Water Cluster Source Ionoptika has been developing for over a decade.

“It’s clear that this new technique will be important for forensic science in the future,” he said.

#securityelectronicsandnetworks.com