First, I never implied disallowing analysis at a crime scene. What I described is a realistic activity criminals do in order to disguise their identity.
Second, "stealing your hair" is a very different thing than stealing license plates off of your vehicle. This should be obvious.
> Someone framing me in this manner is incredibly unlikely, would be disproven by the other broad investigative powers afforded to law enforcement, and, at least in my opinion, is ridiculously less likely than the cameras photographing real criminals.
The point is that it would be you having to defend yourself for something you did not do. Could you successfully do so? Maybe. It depends on what the crime was and if you could afford a skilled enough lawyer.
And therein lies the rub.
You would have to drop tens-of-thousands of dollars in defense of your not being one of the "real criminals." Because the police are not going to sit there and say, "gee wiz, veec_cas_tant could not possibly be a 'real criminal' because they said they are being framed!"
They are going to say, "we can place you at the scene of the crime."