Frierson was driving a car stopped at a red light in July 2001 when a police officer pulled up behind him. The officer noticed that a tail light on the car was cracked, although it was lit. When the traffic light turned green, Frierson turned left without signaling. The officer pulled Frierson over because of the failure to signal and the cracked tail light. After checking Frierson's identification, the officer learned there was an outstanding warrant for his arrest. It later turned out that the warrant was intended for someone else who had wrongfully used Frierson's name and date of birth. After the stop, a weapon was found in the car and Frierson was charged with illegal possession because he was a felon. At trial, the judge let the state use this evidence even though it concluded that the initial stop was unlawful, on grounds that the outstanding warrant was sufficient cause and that the officer relied upon it in good faith. The Fourth District reversed on grounds that the outstanding warrant did not "cure" the initial unlawful stop.