Warrantless Arrests. In certain circumstances, a law enforcement officer may lawfully arrest a person without an arrest warrant. An officer may conduct a warrantless arrest if (1) the officer has probable cause to believe the arrestee has committed an offense in the officer's presence, (2) the officer has probable cause to believe the arrestee has committed a felony and the arrest occurs in a public place, or (3) the officer has probable cause for an arrest and the circumstances are “exigent.” After making a warrantless arrest, an officer must promptly secure a judicial determination of probable cause. The probable cause required to make a lawful warrantless arrest is identical to the probable cause required to secure an arrest warrant.

Probable cause alone is insufficient to justify warrantless entry into a person's home, and warrantless arrests in suspects' dwellings are presumptively unreasonable. Absent consent, only exigencies--such as fear of imminent destruction of evidence, hot pursuit, or immediate threats to the safety of the public or the officers--can justify warrantless entry into an individual's home to make an arrest. Courts disapprove of police conduct that creates exigent circumstances to justify a warrantless arrest in a suspect's home, but will often sustain such arrests when the police can demonstrate that their actions were motivated by legitimate law enforcement needs.

The special protections afforded to dwellings extend to rented premises, hotel rooms, and temporary residential arrangements, but not beyond the premises to hallways, common areas, or areas where there is no legitimate expectation of privacy. Even with an arrest warrant, police may not enter the home of a third person to arrest an individual not living there unless the police have a search warrant or a reasonable belief that the person named in the arrest warrant resides in the home and is currently inside.