> Come to think of it, why is the criminal justice system not "tested"? In other words, set up a mock situation where you know in advance who is innocent and who is not (because it's a setup), and run a mock trial by all the rules using actual jurors, and compare the outcome of the trial to the actual innocence or guilt of the actor?

Probably for the same reason most things are or aren't done - some form of status-quo bias. I mean, someone has to think of the idea, push it, administer it, etc. It's a lot of work. And no one really has an incentive to do that work right now.

Btw, your statement isn't really accurate: >> I think people usually go to prison for the legally correct reason >Or not, if most of the incriminating information was eyewitness testimony, the #1 cause of wrongful convictions:

The fact that eyewitness testimony is the #1 cause of wrongful convictions doesn't tell us anything about the rate at which wrong convictions occur. It's possible for eyewitness testimony to be the #1 cause of wrongful convictions, but for there to be only e.g. 3 wrong convictions a year out of 100k trials. Which would probably be pretty "acceptable".

(I say this because it sounded like you were making the common probability mistake of flipping two things: knowledge of how often a wrongful conviction is caused by eyewitness testimony, and knowledge of how often eyewitness testimony causes a wrongful conviction. Knowing the former doesn't mean we know the latter. Not sure if you're actually claiming this, but wanted to clarify what it sounded like to me).