State of Tennessee v. Dennis R. England

Summary

The Court held that a trained drug-detection dog’s sweep around the perimeter of a lawfully detained vehicle is not a Fourth Amendment search and requires neither probable cause nor reasonable suspicion, provided it does not unreasonably prolong the traffic stop. It further held that the dog’s positive alert, together with evidence of the dog’s and handler’s reliability and the defendant’s suspicious demeanor, supplied probable cause to search the vehicle. Justice BIRCH, dissenting, would have required reasonable suspicion before the canine sweep because the sweep was initiated solely after England refused consent.