O'Brien was a security guard who worked in the parking garage of the Garden Valley Shopping Mall.
In "The Parking Garage", O'Brien was patrolling the parking garage of the Mall when he spotted Jerry Seinfeld urinating in a corner and detained him. Jerry ardently proclaimed his innocence in O'Brien's office, claiming that he had a potentially fatal urinary-related condition called uromysistitus. O'Brien was not persuaded, even after Seinfeld argued that he had a public urination pass issued by the state. As Jerry was held there waiting to be processed by the police, O'Brien continued his rounds and eventually returned with George Costanza, who was detained for the same reason as his friend. The two were ultimately fined and released.
In "The Finale, Part 2," O'Brien is one of the witnesses to the character of the "New York Four" summoned to their trial. At the behest of District Attorney Hoyt, O'Brien testified that Jerry and George urinated in the parking garage.
Trivia[]
- Though O'Brien was unnamed in his appearances, in the former he wore a visible parking tag with the name "O'Brien."