What percentage of cases do you think are like this? My guess is sub 0.01% — it’s just not that common according to the defense attorneys I know. When it does happen, bar complaints fly. My friend tells me that there definitely are wrongful convictions, but it is often not that the person was innocent of a crime, but that they were convicted of the wrong charge. As far as I am concerned, these types of cases seem to be very much the exception rather than the rule — no system is perfect, and I am fully aware of that.
I have said elsewhere that a corrupt district or DA is a caveat to my stance. Ditto with high profile “must try” cases (I was a juror in one of those). That was a district with a corrupt DA — it happens. The cool thing to me is that the dude was disbarred — the system worked.
I will also add that I think universities interpret rules far too generously (more like guilty until proven innocent), and I don’t agree with that at all, but that does not always become a legal matter. When it does, it is often a must-case for political reasons, and plea deals getnwokky then. I’ve said all of this elsewhere.
Es a "for example" I suggest that you read about Mike Nifong's (DA on the Duke LaCrosse rape case) actions and his despicable lying. [1]
This may seriously change your opinion on the subject.
DA's regularily lie and cheat for political gain.
[1] https://en.wikipedia.org/wiki/Duke_lacrosse_case