Which standard is required for a lawful patdown or frisk?

For a lawful patdown or frisk to occur, the key requirement is that the person must be lawfully detained. This standard is rooted in the Fourth Amendment, which protects against unreasonable searches and seizures. The concept of a lawful detention, often referred to as a "Terry stop" (derived from the Supreme Court case Terry v. Ohio), allows law enforcement officers to stop and briefly detain a person based on reasonable suspicion that they are involved in criminal activity.

Once the individual is lawfully detained, the officer may conduct a patdown or frisk for weapons if they have a reasonable belief that the person may be armed and pose a danger to them or others. This is not based on probable cause or the formal charging of an individual; rather, it's about the officer’s immediate safety and the need to ensure that they are not at risk during the encounter.

In summary, the requirement of lawful detention establishes the framework within which an officer can conduct a patdown or frisk, emphasizing the balance between individual rights and officer safety in law enforcement practices.