The Serious Crimes timer (I don't know about the minor crimes timer) does not seem to count down properly, either not counting down at all, or, I think once, freezing halfway down.

I don't know what causes this, but it's especially annoying when you're actually on the recieving end of an arrest for once.

Known issue. I'm still not clear on exactly what causes this, aside from the generic "lag" explanation.

I believe it started around the time the 'Locking Mechanisms' went in.

(which, by the way, I think are a pretty awful idea, but I may not be entirely clear how they work.)

They're totally unrelated.

The locking mechanisms allow released people to leave even if some errant Watchman accidentally left the door to the cell block locked. They were becoming fairly necessary, as I understand it.