That's the question, isn't it? LE uses facial recognition to scan crowds. Now cars are tracked, not using GPS, an observing officer, or a member of the public (who may need to report a crime), but by snarfing video of all the license plates with a geolocated camera, timestamping and OCRing them, and storing the resulting information.
The next thing that pops into my head is the fingerprint. Not because it's "easy" to get, but you also have no reasonable expectation of privacy with them.
Imagine the embarrassment when "no two fingerprints are alike" is finally disproven as some poor bastard is arrested and charged with a crime committed by another person solely on the basis of his thumbprint.
It doesn't seem to embarrass prosecutors too much when they jail someone for five months based on "conclusive DNA evidence" - even though the suspect was in hospital with a blood alcohol reading on 0.4 from two hours before the crime to 12 hours afterwards. And who'd been take to hospital by the same ambulance crew that attended the crime later on and moved the victim… You can see where this is going right? - "The paramedics physically moved both Anderson and Kumra, resulting in the inadvertent DNA transfer…"
How on earth can someone end up in jail for five months under those circumstances?
(Note too, the other suspect jailed for seven months - for, several months before the killing, posting a photo of the future-victim's house to Instagram…)
Not quite charged, but held for two weeks and only released when someone without an alibi of being on the other side of the planet was found to also have matching prints...
The next thing that pops into my head is the fingerprint. Not because it's "easy" to get, but you also have no reasonable expectation of privacy with them.
Imagine the embarrassment when "no two fingerprints are alike" is finally disproven as some poor bastard is arrested and charged with a crime committed by another person solely on the basis of his thumbprint.