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It's official! Laurence Fishburne will join the cast of "CSI: Crime Scene Investigation" this season.

As previously reported, William Petersen is leaving the hit CBS drama "CSI," but sources tell ET this does not signal the end of the series, which continues to be one of the top rated shows on CBS. The actor, who plays detective Gil Grissom, will exit the show at midseason, with the 10th episode of the upcoming season being his last as a regular cast member.

Fishburne -- an Oscar nominee, Emmy and Tony Award winner -- will make his debut in this season's ninth episode.