Which Constitutional Standard Applies to a Police Encounter?

It depends on what happened. Many police misconduct cases involve protections found in the Fourth Amendment, which protects people against unreasonable searches and seizures, and can apply to your body, home, vehicle, and belongings.

Different encounters are measured differently. Where force was used during a seizure, courts examine whether it was objectively reasonable under the circumstances, considering factors such as the seriousness of the suspected offense, whether someone posed an immediate threat, whether the person was resisting or attempting to flee, and the circumstances facing officers at that moment. An investigative stop usually requires reasonable suspicion, an arrest generally requires probable cause, and whether a search was lawful can turn on warrants, consent, probable cause, and recognized exceptions.