What must be present for a Terry frisk to be conducted?

For a Terry frisk to be conducted, reasonable suspicion is required. This standard is derived from the Supreme Court case Terry v. Ohio, which established that police officers can stop and briefly detain a person based on reasonable suspicion that the individual is involved in criminal activity.

Reasonable suspicion is a lower legal standard than probable cause, allowing officers to act based on specific and articulable facts that suggest a potential threat or crime is afoot. The purpose of a Terry frisk is to ensure the safety of the officer and the public by allowing a quick pat-down of the outer clothing for weapons if the officer reasonably believes that the person may be armed and dangerous.

While probable cause pertains to arrests and searches requiring a warrant, and clear evidence of a crime exceeds the threshold needed for an initial encounter, reasonable suspicion specifically addresses the necessity for a brief investigative stop and frisk. Permission from the subject is not required for a Terry frisk, as the standard for conducting such a search is based on the officer's reasonable suspicion rather than the subject’s consent.