Watching Dexter this 'blood splatter anaysis' seemed beyond ridculous to me. I thought there were no way it would be a thing in the US in the way portrayed.
But then I learn truth detectors are? What more movie tropes are not tropes?
But then I learn truth detectors are? What more movie tropes are not tropes?
https://www.theguardian.com/us-news/2022/apr/28/forensics-bi...
It turns out just throwing handcuffs on someone is enough to get a false positive GSR test. And matching a shell casing to a specific gun is essentially impossible.
The false positive rates on forensic "tests" are hard to study because no one has an incentive to, and if you go digging you'll find how bad they can be. Like for example K9 units have about a 50% false detection rate (dog indicated but no drugs/weapons/bombs found). If a cop told you they flipped a coin to decide whether to search a car then the search would be tossed out of evidence immediately!
It's a factless and truthless system.