O'Brien is a fictional character portrayed by Charles Socarides in the TV series Law & Order.
They appear in 1 episodes out of a total of 501 aired so far
O'Brien is also portrayed by Chuck Margiotta.
Episodes1
Tombstone
episode S15.E20 april 2005A lawyer from a prestigious corporate law firm is murdered. One of the firm's senior partners is reluctant to testify against the accused for selfish reasons. Detective Green is critically wounded escorting a reluctant witness.