In Illinois v. Caballes, 543 U.S. 405, (2005), a trooper stopped motorist Caballes for speeding on an interstate. When the officer reported the traffic stop to dispatch, a second trooper overheard the transmission and immediately headed for the scene with his narcotics-detection dog. The first trooper had Caballes in his patrol car and was in the process of writing a warning ticket when the second trooper walked the dog around Caballes' vehicle and the dog alerted at the trunk. A subsequent search of the trunk resulted in the discovery of marijuana. The trial judge, finding the officers had not unnecessarily prolonged the stop, denied Caballes' motion to suppress the evidence, and Caballes was convicted of a narcotics offense. The Appellate Court affirmed, but the Illinois Supreme Court subsequently reversed the conviction finding the use of the dog unjustifiably enlarged the scope of a routine traffic stop. The U.S. Supreme Court vacated and remanded, noting they "accepted the state court's conclusion that the duration of the stop . . . was entirely justified by the traffic offense and the ordinary inquiries incident to such a stop."