“Every now and again I have to sack a decent copper for police brutality, and I do sack them, you may be sure of that, for doing what the average member of the public might do if they were brave enough and if they had seen the dying child, or the remains of the old woman. They would do it to restore in their mind the balance of terror. Often the law treats them gently, if it worries about them at all, but a copper, now, he’s a lawman – certainly if he works for me – and that means his job stops at the arrest, Mister Stratford. So what’s stopping me from squeezing the life out of a murderer who has broken into the room he thought would hold my little boy with, oh, dear me, such a lot of little knives? Why will I squeeze him only to unconsciousness, while despising myself for every fragment of breath I begrudge him? I’ll tell you, mister, that what stands between you and sudden death right now is the law you don’t acknowledge.”

– from “Snuff,” by Terry Pratchett