What is police protocol when dealing with a psychopath?

Answer 1

First of all, no one carries around a sign on their chest that says "I am a psychopath." The officers must gauge their reactions and their approach to EACH and EVERY citizen contact they make with an eye towards making a quick evaluation of the individuals mental capacity and reaction to them. If their actions are resisted or they are violently attacked, they must, and will, defend themselves.

Usually, only after a situation is over with, and in the glow of 20/20 hindsight, can someone make a determination that the individual they were dealing with may have been "psycho."

ALSO: there is the very real factor (as any experienced officer can tell you) that there are those who simply 'act psycho' in an effort to avoid (or intimidate) any possible interaction with the police.

As is so often the case with police/citizaen interactions, every situation stands on its own particular set of circumstances and facts.