You're essentially appealing to the natural right to self defense. I'll grant you the constitution isn't a suicide pact -- if people are in imminent danger of death or disability then they or anyone else has a natural right to swiftly and severely deal with the transgressor. Any society that doesn't will perish, this supersedes all laws written by man.
However, after that happens there will be judgement. And the judgement is finding that quite often these renditions without process were not so justified. If you are going to act without process, you damn well better be right, and if you are not you should be judged as if you acted violently lawlessly.