Main Menu

Your Fingerprint Is All Someone Needs to Know You Used Cocaine

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.