Christopher had established himself in NYC, Los Angeles and regional theater before shifting to films in the 70s. He also spent some time in Paris as a member of the Living Theatre, performing in street theater and experimental films. While overseas he has a part in Fellini's experimental documentary on Federico Fellini's "Roma" (1972). Back stateside, Christopher appeared in "9/30/55" (1977) and Robert Altman's "A Wedding" (1978), as the brother of the bride and son of Carol Burnett and Paul Dooley.
Christopher also has appeared in several worthy indies with gay themes. He was a maligned homosexual teacher in "The Disco Years" segment of the omnibus film "Boys Life" (1995) and one of the guests in Randal Kleiser's "It's My Party" (1996). Christopher has remained active on the stage, winning kudos for his portrayal of gay mathematician Alan Turing in the Los Angeles production of "Breaking the Code". He also provided the calming off-stage voice of an AIDS project doctor in a Los Angeles production of "A Quiet End".