A former child actor with the National Shakespeare Festival Ontkean first came to prominence in the TV series "The Rookies" (ABC, 1972-74). He has appeared in several films, notably opposite Paul Newman in "Slap Shot" (1977) and in the tame homosexual love story "Making Love" (1982), which reunited him with his TV wife Kate Jackson. He is best known to contemporary audiences as straight-arrow police chief Harry S. Truman in David Lynch's TV soap-opera-with-a-twist, "Twin Peaks" (1990). He reprised the role in Lynch's 1992 feature "Twin Peaks: Fire Walk With Me". Ontkean also has appeared in many TV movies including opposite Jodie Foster in the WWII thriller "The Blood of Others" (HBO, 1984) and memorably as an accused murderer in "In a Child's Name" (CBS, 1991).