For the state, Assistant Arizona Attorney General Joseph Parkhurst argued that for a search to be constitutional under Terry v. Ohio and subsequent opinions, the officer need only reasonably believe that the searched is armed and dangerous.  For the defendant, Andrew Pincus argued that a officer must believe both that a the searched is armed and dangerous AND that criminal activity is afoot. 

Interestingly, and for the first time, the Supreme Court may now need to decide when a traffic stop begins and ends.  A sizable portion of the argument centered around whether Johnson, the passenger was seized during the traffic stop as well as the larger issue of when a traffic stop actually begins and ends.  In fact, to rule here, the court may actually have to decide when a traffic stop begins and ends.