Thomas Dekker (“Terminator: The Sarah Connor Chronicles,” “A Nightmare on Elm Street”) has signed on to HBO Films’ “Cinema Verite,” a behind-the-scenes look at the 1973 groundbreaking documentary “An American Family,” Dekker, who will play Lance Loud, joins Tim Robbins, Diane Lane and James Gandolfini. Robbins and Lane will play his parents, Bill and Pat Loud, while Gandolfini has the role of “American Family” producer Craig Gilbert.

In 1971, Gilbert and his crew shot more than 300 hours of 16mm color film of Santa Barbara couple Bill and Pat Loud and their five children. After over a year of editing, the 12-hour documentary series aired on PBS in 1973.

Lance, 20 at the time, was openly gay, and the series depicted his life in New York City. As the first out character on television, he created national controversy and became an early LGBT icon.

Following the show’s airing, Lance returned to New York, where we was befriended by Andy Warhol and played in a punk band. He later moved to Los Angeles and worked as a journalist. For decades, he struggled with a drug problem and the hollowness of the fame that was foisted upon him at such a formative age. In 2001, at the age of 50, Lance died from liver failure, brought on by a coinfection of HIV and hepatitis C. A few months before his death, Lance asked two of the series’ original filmmakers, Alan and Susan Raymond, to film a final episode of his family’s story. The entire Loud family, save for one brother, agreed to participate in “Lance Loud! A Death in An American Family.”

Watch this 1973 Dick Cavett interview with Lance Loud.