Made his Broadway debut in "Lost in Yonkers."
Appeared with his wife, Marg Helgenberger, in the CSI: Crime Scene Investigation (2000) episode, CSI: Crime Scene Investigation: Weeping Willows (2005). According to Helgenberger in the DVD commentary, he was uncomfortable treating her the way he does, even though it was just a fictional encounter.
Has a son named Hugh.
During the "radical" 1960s, Alan became a member of the Black Panthers and was an active protester of the Vietnam War.
Met second wife actress Marg Helgenberger while both were appearing in the daytime soap Ryan's Hope (1975) in 1984. Alan was married at the time to actress Robin Bartlett. They hooked up again by accident at a Los Angeles bank two years later (Alan was then divorced) and married in 1989. They have one son and have appeared in several projects together, including the Lifetime TV-movie Giving Up the Ghost (1998).