Denial of motion to suppress evidence reversed where police unlawfully prolonged vehicle stop after determining there was no Vehicle Code violation. Sacramento police stopped Suggs’ car because it displayed only paper plates and the officer did not see any registration or recent purchase documents in view. As the officer approached the vehicle, he saw a temporary registration attached to the rear window, which was tinted. Even though the officer discovered that he had no basis for writing a citation, he proceeded to ask Suggs and his passenger questions and ran a records check, which revealed their licenses were suspended and the passenger was on probation. During a probation search, police found a gun and drugs. Suggs pleaded no contest to possession of a concealed gun after denial of his motion to suppress. He appealed. Held: Reversed. A seizure for a traffic violation justifies a police investigation of that violation. The “tolerable duration [of the traffic stop] is determined by the seizure’s ‘mission’—to address the traffic violation that warranted the stop.” (Quoting Rodriguez v. United States (2015) 575 U.S. 348, 354 [alterations in original].) Here, the detention became unlawful when the officer saw the registration in the window and realized there was no Vehicle Code violation, and then made inquiries aimed at finding evidence of criminal wrongdoing separate from the perceived Vehicle Code violation.