Our office really likes the following U.S. Supreme Court opinion that holds that the duration of a traffic stop is limited to the time reasonably necessary to address the “seizure’s mission.” This means that a detention which exceeds this duration is a prolonged detention and any search taking place thereafter is a Fourth Amendment violation unless new suspicions by the officer support such a continued detention and search. The case certainly must be used carefully, but is still potentially good. To read a summary about the opinion, click here.
http://www.greghillassociates.com/dog-sniff-of-car-improper-if-driver-driving-on-the-shoulder.html.