Originally Posted by BlueLightning
It was already taken care of.
"It won't matter. The head guys make bail, sure... but the mid-level guys, they can't, and they can't afford to be off the streets long enough for trial and appeal. They'll cut deals that include some jail time. Think of all you could do with 18 months of clean streets."
With Dent's "heroic" death, and setting up the Dent Act, the police had enough power to round up the leftovers. Though it would have taken some time, at least those 18 months. It's naive to think all would have been done instantly.
When I say the audience can infer other things happened to Bruce, I mean guys the Police can't handle. Again, see jakinj's webcomic. Bruce makes 9 major appearances as Batman and so far, one of those is against Mr Freeze. Again, allowing the audience to use their imagination to create a richer, grander, more filled universe.
Then you can go into the Police rounding up small time criminals and Batman having a further diminished presence in Gotham.