Cocaine via Fingerprints will soon tell cops if suspects are guilty


Cocaine via Fingerprint – Call it a line detector—law enforcement agencies may soon have a way to test for cocaine use through a quick, non-invasive fingerprinting technology.

Rather than looking for trace amounts of cocaine itself, a new test developed by a team of researchers led by the University of Surrey looks for the products of cocaine metabolism. When the body breaks down cocaine, it produces benzoylecgonine and methylecgonine which are detectable in blood, urine—and even the sweat.

“We can distinguish between cocaine having been touched,” the study’s lead author, Dr. Melanie Bailey, told Motherboard, “and cocaine having been ingested.” This prevents false positives, which are very possible in a society where a majority of bank notes and some other common objects hold detectable amounts of cocaine and other illicit substances.

The Netherlands Forensic Institute, the National Physical Laboratory, King’s College London, and Sheffield Hallam University were also involved in the study.

The team has yet to collect detailed results on the effects of dosage or timing, but in general sweat tends to show traces of drug use more quickly than urine, and less quickly than blood. Cocaine generally appears in urine about four hours after ingestion, and remains detectable for over a week.

Bailey said the basic strategy of looking for the telltale byproducts of drug metabolism, rather than for the drugs themselves, “applies to most drugs, in theory.”

One intriguing implication of fingerprint-based testing is that forensic teams might be able to use crime-scene evidence to infer something about a suspect’s drug habits. And, of course, fingerprints are inherently a form of identification, making the method immune to drug testing work-arounds like purchasing clean urine from a third party.

The study used a form of mass spectrometry called Desorption Electrospray Ionisation (DESI) to look for its cocaine marker molecules (these huge, million-dollar rigs won’t be making their way into house-arrest anklets any time soon). Still, Bailey says that ongoing research in miniaturized mass spectrometers could change that. Portable-sized DESI rigs soon sell for $100,000 or less, “which is actually cheaper than what some hospitals are currently using for drug testing.”

The technology will need extensive testing for reliability and dosage sensitivity before making its way into active use, but the team hopes to have working units in the hands of medical law enforcement personnel within ten years, at the most.

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