He also starred in the films To Live and Die in L.A. (1985), Manhunter (1986), Young Guns II (1990), Fear (1996), The Contender (2000), Detachment (2011), and Seeking a Friend for the End of the World (2012).

[citation needed] Petersen made his film debut with a bit part in Thief (1981), directed by Michael Mann.

He also claims to have done this because, while rehearsing for a play in Chicago, his dialogue was always coming out like Graham's; he dyed his hair so he could look in the mirror and see a different person.

Instead, he worked on the 1987 HBO made-for-TV movie Long Gone as a minor league baseball player and manager named Cecil "Stud" Cantrell.

[17] In 1993, Petersen appeared in a CBS TV miniseries, Return to Lonesome Dove, as former Ranger Gideon Walker.

[18] He played Steven Walker, a father who stops at nothing to break up the relationship between his daughter and her vicious boyfriend in Fear (1996).

[19] Petersen played Governor Jack Hathaway, an unscrupulous candidate for vice president following the death of the incumbent, in The Contender in 2000.

[20] He appeared uncredited in the noir thriller Mulholland Falls as a character who finds himself on the violent receiving end of a Los Angeles police squad's tactics.

[24] Petersen took a break from CSI in 2006 to appear in a five-week run of the Trinity Repertory Company production of Dublin Carol by Conor McPherson, in Providence, Rhode Island.

[26] On July 15, 2008, the Associated Press reported that Petersen was leaving the show as a regular following Season 9's tenth episode in order to pursue more stage-acting opportunities, but that he might return for guest spots.