What legal principle justifies the use of "stop and frisk" procedures?

The use of "stop and frisk" procedures is primarily justified by the legal principle of reasonable suspicion. This principle allows law enforcement officers to stop an individual and briefly detain them if they have a particular set of facts or circumstances that would lead a reasonable person to believe that the individual is involved in criminal activity.

Reasonable suspicion is a lower standard than probable cause and does not require evidence that a crime has been committed. Instead, it is based on articulable facts that lead the officer to suspect that a specific person is engaged in criminal activity. This legal concept was established in the landmark Supreme Court case, Terry v. Ohio, which upheld the constitutionality of such stops designed to protect officer safety and prevent crime.

The other options do not appropriately apply in the context of stop and frisk. Probable cause is a higher standard required for arrests and obtaining search warrants, while legal consent involves the voluntary agreement of an individual to allow a search. A judicial order, meanwhile, refers to formal instructions issued by a judge, which is not relevant to the immediate and quick assessments made by officers during a stop. Thus, reasonable suspicion is the correct legal principle that justifies these procedures.