The police cannot arrest a person or search their property without a legal warrant. There are some exceptions however.The arrest may be made with or without a warrant, depending on the circumstances. So, what is an arrest? The police don't need a warrant if they have a reasonable fear that their safety, or that of the public, is in imminent danger. The plain view doctrine. Officers need a warrant for an arrest if they want to arrest a person at their home or in a public place. Warrantless searches are permitted only if the occupant of the home consents to the search or there are "exigent circumstances. This directive: A. outlines the Department policy for developing, obtaining, reviewing, serving, and returning search warrants. Law enforcement does not need a warrant for a felony arrest in a public place, even if the arresting officer has time to get a warrant.