Man, there just isn't enough jail space to hold all of these guys even if they did want to catch them ... and even if they did, where would they put all of the violent felons?
All they can do is cherry-pick, and make examples and scapegoats of the few, in the hopes that it will act as a deterrent for the other 80% that they know they can't get a hold of.
OK, not that I'm saying it's OK, it's not. But they really want to incarcerate the guys they're afraid of, and these ain't them.
JJ