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.
The case arises out of defendant Carlocito Slim’s convictions of two federal crimes: attempted commercial sex trafficking of a minor, and attempted enticement of a minor for sexual activity using a facility of interstate commerce. After viewing an online classified advertisement seemingly posted by a 20-year-old woman, Slim twice texted the ad’s number, asking whether the woman was available and whether she offered massages. Unbeknownst to Slim, the ad had been posted by a male South Dakota law-enforcement agent, and the images of the woman in the ad were of an adult female law-enforcement officer that had been altered to make her look younger.
