Fingerprint test can distinguish between those who have taken or handled heroin

A state-of-the-art fingerprint detection technology can identify traces of heroin on human skin, even after someone has washed their hands -- and it is also smart enough to tell whether an individual has used the drug or shaken hands with someone who has handled it.

from Top Technology News -- ScienceDaily https://www.sciencedaily.com/releases/2019/11/191111204738.htm