False negatives in criminal justice

Having written about false negatives in steroid testing leads me naturally to ask: how serious is the false negative problem in criminal justice?

It's pretty clear that in law, we also try to minimize false positives, which means that there are criminals who evade justice. I wonder if, and how, one would assess the probability of a criminal not getting caught. Anyone have seen or know about such studies?

It would, of course, not be easy to measure such a thing since one may need a lot of confessions. But there may be smart ways around it. For instance, maybe a large business has tracked the total amount of stuff stolen from its stores over a period of time, and also the total value of goods stolen by those caught red-handed.