For arrests made without warrants, the probable cause for the arrest must be determined at a hearing no later than 48 hours after the arrest, barring an emergency or other extraordinary circumstance. A custodial arrest may be made for a fine-only crime if authorized by state law. The lawfulness of an arrest does not depend on the subjective motivations of the arresting officer.
A felony arrest may be made in public based solely on probable cause, and without either a warrant or exigency.
Entry into a dwelling to arrest the homeowner may not be made in the absence of an arrest warrant or exigency.
Entry into a dwelling to arrest a person who is not the homeowner or a resident may not be made without a search warrant for that person or exigency.
A blood test is a minor intrusion that is not unreasonable following an arrest for drunk driving; but surgery to obtain a bullet requires a compelling government need in order to be reasonable.
Deadly force may be used to arrest a fleeing felon who poses a threat of serious physical harm to the police or others.