Forensics at Your Fingertips

I’m actually not talking about fingerprints, today. Although that’s an interesting, and somewhat fraught, topic in forensics, for one very good reason: there is no established minimum. You can, in theory, take a mere three or four points of reference matching an unknown print to a known, and call it identified. That would be silly, but sadly, there’s nothing to say you can’t do it. Yet. I hold out hope for a more rigorous standard in coming years as it is apparent forensic fingerprinting is not held to a high enough bar to cross for admissible evidence. No, what I’m talking about today is what makes up the fingerprints themselves.

Locard’s principle, that anything we come in contact with transfers a trace of itself to us, and we to it, has never been taken to such miniscule levels. We now have the technology to test a microscopic trace of an unknown person left at a crime scene, and it can reveal to us what sex they are, what they look like down to hair and eye color, their genetic identity, and now, even what drugs they may have in their system. Touch DNA is what can be extracted from the nuclei of skin cells left behind in fingerprints. We shed our dead cells constantly, and although tracking a single cell authoritatively to a perpetrator to say ‘so and so was here at this time’ is a nigh-impossible task, using the cells in a fingerprint allows forensic analysts to declare that the print, the DNA; they go together.

And now, four classes of illicit drugs can be detected from fingerprint sweat, as well. The current test is to allow for presumptive detection of cannabis, cocaine, opiates, and amphetamines from the finger of a living or dead body. But it doesn’t take much of a leap forward to extract that information from a fingerprint. For now, being able to quickly detect illicit drugs and then confirm with the more time-consuming methods that are more precise is enough to be an exciting new tool in analyst’s ability to aid in law enforcement. Also, given some time, I’m sure that other drugs and substances will be added to the test, as well.


7 responses to “Forensics at Your Fingertips”

  1. That “tricorder” gadget is looking ever less distantly fictional.

  2. Sanford Begley Avatar
    Sanford Begley

    Today I took a drug test for work. I stuck an oversized q-tip in my mouth for two minutes and stuck it back in the bottle. A couple of minutes later I had passed the test. I didn’t even study for it. This is a far cry from “pee in a bottle and we’ll get back with you in a few weeks”

    1. Or from a skeevy-looking clinic where you go in a dirty bathroom with no door and pee in a cup while someone watches you… I really really hated that. Thank goodness I have no modesty.

      1. did that a few times in the army, one time got dinged for narcotics… well duh, the hospital gave me a seven day supply of tylenol 3,and i was on day 4….

  3. Margaret Ball Avatar
    Margaret Ball

    Remind me to check with you the next time I can’t think of any forensic way to identify whodunnit!

    1. Happy to brainstorm with you, and it’s always a fun avenue to wander down with research.