Joslin was born in Melrose, Massachusetts in 1946 and spent his youth in Lynnfield and Cumberland. He earned his Bachelor of Arts degree at the University of New Hampshire in 1972 and his Master of Fine Arts degree four years later from the Rhode Island School of Design.
In addition to his work in filmmaking, Joslin taught at Hampshire College and the University of Southern California. He began making short films in 8mm at the age of 14.
Joslin's notable works include Blackstar: Autobiography of a Close Friend (1976),a film about coming out and growing up as a gay filmmaker, and Architecture of Mountains (1979),a dream-based experimental film.
In 1981, Joslin decided to leave academia to pursue a career as a writer/director in Hollywood. He formed the Primary Colors Company with Selise E. Eiseman and worked as an uncredited casting assistant for Zoetrope Studios.
When Joslin and his long-time partner Mark Massi were both diagnosed with AIDS, he decided to create a video diary: Silverlake Life: The View From Here (co-directed by Peter Friedman, 1993).
Sadly, Joslin passed away on July 1, 1990, in Los Angeles.
