Which of the following formats of jurisdiction allows arrest without a warrant?

The correct response is rooted in the principle of a citizen's arrest, which is grounded in common law. This format of jurisdiction allows an ordinary individual to detain someone whom they believe has committed a felony, provided the individual witnessed the crime or has reasonable grounds to suspect it. This authority does not require a warrant.

In contrast, investigative detention refers to the temporary stopping and questioning of a suspect by law enforcement based on reasonable suspicion, but it doesn't grant the power to formally arrest without probable cause or a warrant. A search warrant is a legal document that authorizes law enforcement to search a specific location for evidence of a crime and is required for any search; it does not apply to the arrest of a person. Lastly, a mutual aid agreement typically pertains to cooperation between law enforcement agencies and does not signify jurisdictional authority necessary for making an arrest without a warrant.

Understanding these distinctions underscores why a citizen's arrest is the only format in this context that permits an arrest without needing a warrant.