An officer must have what to legally stop and detain a person?

To legally stop and detain a person, an officer must have reasonable suspicion. This standard is based on the idea that an officer has a specific and articulable reason to believe that a person is involved in criminal activity. Reasonable suspicion is a lower standard than probable cause, which is required for an arrest or for a search warrant.

When an officer observes behavior that leads them to believe a person may be engaged in criminal activity, such as unusual conduct or a pattern of behavior, they can initiate a stop. This allows the officer to investigate further, often through questioning or a brief detention, to determine whether there are grounds for further action.

While a warrant is a legal document authorizing an arrest and a higher standard of evidence, and probable cause is necessary for an arrest, these are not required for a temporary stop. Additionally, a citizen's complaint may lead to reasonable suspicion, but in itself does not provide the legal basis for a stop. Thus, reasonable suspicion is the correct standard for an officer to stop and detain someone effectively and legally.