Excerpted from The Atlantic story by Rod McCullom

A raft of sensitive new fingerprint-analysis techniques is proving to be a potentially powerful, and in some cases worrying, new avenue for extracting intimate personal information—including what drugs a person has used.

That’s right: The new techniques can determine, from a single fingerprint, not whether you have handled these drugs, but whether you have taken them.

The new methods use biometrics to analyze biochemical traces in sweat found along the ridges of a fingerprint. And those trace chemicals can quickly reveal whether you have ingested cocaine, opiates, marijuana, or other drugs. One novel, noninvasive forensic techniquedeveloped by researchers at the University of Surrey in the United Kingdom can detect cocaine and opiate use from a fingerprint in as little as 30 seconds.

The researchers say they hope to expand the range of controlled substances that can be detected, which could include methamphetamines, amphetamines, and marijuana. The test can be modified to detect therapeutic drugs prescribed by physicians too.

Needless to say, the technology has titillated law-enforcement and corrections officials, and it may have useful applications for professionals working in drug treatment, elder-care centers, and other inpatient and outpatient facilities. For all of its heady new potential, however, the emergence of technologies like these has some observers feeling a bit uncomfortable about how, where, and to whom they are likely to be applied. More pointedly, the ability to glean detailed information about a person from a mere fingerprint—Do they smoke cigarettes? Use marijuana? Enjoy fatty foods? Drink alcohol?—raises a number of potentially knotty questions of privacy and consent.

You can read the full story here.