In United States v. Carlocito Slim (No. 21-2693), the U.S. Court of Appeals for the Eighth Circuit rejected the argument that an arrest by South Dakota law-enforcement officers was unreasonable because the officers lacked authority under state law to arrest the defendant for a federal crime. Regardless of South Dakota law, the court held, whether an arrest complies with the Fourth Amendment does not require reference to the arrest's legality under state law; an arrest by state officers is reasonable under the Fourth Amendment if it is based on probable cause.