THE SHIELD (TV series, Season 6 - 2007)

At the end of season 5 Curtis 'Lem' Lemansky, one of Vic's original Strike Team members, was found murdered. Vic picks up the new season where he left off, vowing to find Lem's killer and take revenge at all cost. What Vic doesn't know is that Lem's killer is one of his own, Strike Team member, friend, and co-conspirator in Vic's original sin, Detective Shane Vendrell.

Detective Kevin Hiatt (Alex O’Loughlin) was brought in to episode 4, “The New Guy,” to replace retiring Detective Vic Mackey as head of the Strike Team.

(Credit: tv.ign.com)