Traffic stop was in violation of the Fourth Amendment, as the questioning into criminal history continued past the point at which the computerized driver's licence check had been completed.
http://www2.ca3.uscourts.gov/opinarch/172739p.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Not written by a barrister. The name was thought up by a second-year American law student sitting in a coffeehouse in Manhattan. Neither an authoritative statement of the law nor legal advice.
Don't rely. Quick work.