Laurence Fishburne leaving "CSI"

(CBS/AP) "CSI" will be down one investigator when it returns for its 12th season this fall.

Actor Laurence Fishburne, who plays Dr. Raymond Langston in the CBS crime drama, is leaving the show, according to a person with knowledge of the situation.

The person spoke on condition of anonymity Tuesday because the network has yet to announce Fishburne's departure.

Fishburne joined the "CSI" cast as Dr. Raymond Langston midway through the 2008-09 season. He stepped in to replace departing star William Petersen.

The person says CBS and the show's producers are taking Fishburne's departure in stride, aware that his movie career made a long TV tenure unlikely. His film credits include "The Matrix" films, and he's in the upcoming "Contagion" with Matt Damon.

"CSI: Crime Scene Investigation" continues to rank among the 20 top-rated shows and also stars Marg Helgenberger, Geroge Eadds and Paul Guilfoyle.