Reasonable belief. The Supreme Court’s ambiguous use of this term in Arizona v. Gant transformed what could have been a clear logical holding into a source of potential uncertainty. Consequently, lower courts have struggled to interpret the reasonableness of police automobile searches subsequent to the arrest of a vehicle occupant. By endorsing an entirely new automobile search authority—one that is triggered by reasonable belief that evidence related to the offense of arrest may be found in the automobile—police search authority will in many cases be expanded. Reasonable belief that evidence related to the arrest may be in the automobile operates as a procedural tether, linking the probable cause of the arrest to the search for that specific evidence. Interpreting reasonable belief as a synonym for reasonable suspicion is inconsistent with the most fundamental principle in search law: pure evidentiary searches may only be reasonable when based on probable cause. Gant’s articulation of reasonable belief presents a new source of search authority, distinct from both the traditional authority granted by a search incident to a lawful arrest and the authority granted by probable cause. Viewing the Court’s decision in Gant as a procedural tether—albeit one with necessary substantive overtones—is, despite first impression, neither a hindrance to police procedure nor a detriment to the public good.