Well, it seems the cops can't win. Since crimes like murder are irreversible, people will ALWAYS clamor to get the criminals BEFORE they commit their crimes (after all, THEY could be next, and they consider a few murders too high a price to pay for civilization) since after the fact is just too damn late. How does the police deal with all the anguished outcries of, "Why didn't you get them sooner?!" when "We're doing the best you let us" is NOT an acceptable answer?