LOS ANGELES – “CSI: Crime Scene Investigation” has solved the mystery of who will replace departing CBS series star William Petersen: It's Laurence Fishburne.

Fishburne, an Emmy and Tony winner, will be introduced in the ninth episode of the upcoming 10th season, the network told The Associated Press on Monday. He'll play a forensics scientist with a secret.

Fishburne is a “CSI” newcomer in more ways than one. Asked if he's a fan, he told a teleconference Monday that he was embarrassed to admit he'd never watched before he was approached by producers.

“But I am now,” he said. He screened past episodes that were engaging and “kind of dark and moody, like the work I've been involved in,” he said.

“Wow, this will work,” Fishburne recalled thinking.

He was their top choice, said executive producers Carol Mendelsohn and Naren Shankar, with a deeply intelligent approach to his work that matches the drama's spirit.

This is the first ongoing series role for the in-demand film and stage actor since, improbably enough, he played Cowboy Curtis on “Pee-wee's Playhouse” in the late 1980s. He's not stepping away from movies with “CSI,” Fishburne said, but embarking on a “welcome change.”

Fishburne will play a college lecturer and former pathologist who is focused on why people commit acts of violence. The character is nameless for now but has been dubbed “The Professor.”

The air date for Petersen's final episode has yet to be determined but will be early next year. Petersen has been with the series since it debuted in fall 2000 and will remain a “CSI” executive producer, the network said.

Fishburne's character has a deep connection to his work: “The Professor” shares certain biological characteristics associated with aggressiveness and criminal behavior, Shankar said.

Shankar said the show wasn't backing away from CBS programming chief Niña Tassler's previous description of the character, in which she said he shared the genetic makeup of serial killers.

Subsequent research has since shown that “in reality, there is no such thing,” so the character is changing course, Shankar said. How his nature will play out in stories has yet to be determined, he and Mendelsohn said.

Fishburne's character, whom Tassler said was keeping his background to himself, meets members of the “CSI” team during a murder investigation and ends up joining them.

Fishburne, 47, received an Oscar nomination for his portrayal of Ike Turner in 1993's “What's Love Got to Do With It” and a Tony in 1992 for “Two Trains Running.” He was a Tony nominee this year for the one-man show, “Thurgood,” about Supreme Court Justice Thurgood Marshall.

His film credits include the “Matrix” sci-fi films, in which he played Morpheus; “Apocalypse Now”; “The Color Purple”; “Mystic River”; “21”; “Akeelah and the Bee”; and “Biker Boyz.” He also is a writer and director.

“CBS asked us, 'Who's at the top of your dream list?'” Mendelsohn and Shankar said in a joint statement. “Without hesitation, we said Laurence Fishburne. He is a powerful and intense actor, with an incredible range.”

Fishburne earned an Emmy for the 1993 premiere episode of Fox's “Tribeca” and another for the movie “Miss Evers' Boys,” which marked rare TV projects for the actor. Early in his career, he appeared in shows including “Miami Vice” and “Hill Street Blues.”

The long-running “CSI” remains key for CBS: It finished last season as the network's top-rated series, ranking No. 9 among all shows with an average weekly audience of 17 million. Spinoffs “CSI: Miami” and “CSI: New York” ranked 16th and 28th, respectively.

Producers have been mum about upcoming plot points. But they said Petersen's character, Gil Grissom, will be reappraising his life after years of high-tech forensics investigations with the Las Vegas Police Department and after facing personal turmoil.

“CSI,” which begins its new season Oct. 9, is ready to deal with Petersen's loss, said Shankar.

“What makes shows go off the rails is they forget who they are. We're a crime-mystery-forensics drama” and that won't change, Shankar said in July.

CBS is a division of CBS Corp.

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