Psych: Season 4, Episode 5

4 - 5: Shawn Gets the Yips

As Shawn, Gus, Lassiter, and Juliet are celebrating Buzz McNab's birthday in a police bar, somebody attempts to rob the place and engages in a gunfight with Lassiter. It is believed that the incident was a random attempt at robbery until Shawn reveals that the gunman (Stephen Lang) was targeting a cop.