A powerful, brooding figure in features and on television since the early 1980s, William Petersen explored the darker corners of the lawman's psyche in "To Live and Die in L. A." (1985) and "Manhunter" (1986) before becoming a household name on "CSI: Crime Scene Investigation" (CBS, 2000-15). A veteran of the Chicago theater community, he burst onto the Hollywood scene with forceful turns in the aforementioned crime dramas, but neither had the box office clout to turn him into a major movie star. Instead, he concentrated on the stage while delivering consistently believable turns in films like "Young Guns II" (1990) and "Fear" (1991), as well as numerous television efforts. His cool, withdrawn investigator Gil Grissom on "CSI" thrust him into the limelight, making him a major TV star, but he walked away from the hit series in 2008 to return to his roots. One of the most eclectic figures in entertainment, his professional choices and performances earned the enduring respect of his peers and admirers.