CSI ran for 15 successful seasons, providing an entertaining mixture of both investigation and climactic character-driven storylines. Throughout its successful run, a core group of characters dominated most of the juicy episodes. Ever wonder what happened to the cast? Follow us as we reveal your favorite CSI stars, then and now.
William Petersen As Gil Grissom – Then
The original leader of the team, Gil Grissom was played by To Live And Die In L.A. star William Petersen. For the first eight seasons, Petersen appeared in each and every episode, before leaving the main cast.