Under what legal standard is a frisk justified?

A frisk, which involves a limited pat-down of a person's outer clothing for weapons, is justified under the standard of reasonable suspicion. This standard allows law enforcement officers to conduct a frisk if they have specific and articulable facts that lead them to believe that a person may be armed and dangerous, even if they do not have probable cause to make an arrest.

Reasonable suspicion is a lower threshold than probable cause, requiring something less than a belief that a crime has been committed. It provides officers the necessary discretion to protect themselves and others in situations where they perceive potential threats. The U.S. Supreme Court established this standard in Terry v. Ohio, recognizing the balance between individual rights and the need for police to ensure safety during encounters.

The other standards mentioned, such as probable cause and beyond a reasonable doubt, are used in different contexts, primarily for arrests and securing convictions, respectively. Clear and convincing evidence carries a higher burden than reasonable suspicion, requiring a clearer demonstration of the merits of a case, typically in civil matters rather than in the context of brief investigative stops.