William O. Douglas

“ The whole momentum of criminal law administration should be in precisely the opposite direction, if the Fourth Amendment is to remain a vital force. Except in rare and emergency cases, it requires magistrates to make the findings of 'probable cause.' We should be mindful of its command that a judicial mind should be interposed between the police and the citizen. ”

“ If the police see a crime being committed they can of course seize the culprit. If a person is fleeing the scene of a crime, the police can stop him. And there are the cases of 'hot pursuit' and other instances of probable cause when the police can make an arrest. But normally an arrest should be made only on a warrant issued by a magistrate on a showing of 'probable cause, supported by Oath or affirmation,' as required by the Fourth Amendment. ”

“ But for the Fourth Amendment they could fashion the rule for arrests that the Court now approves. With all deference, the requirements of the Fourth Amendment now make that conclusion unconstitutional. ”