Actor Sean Penn has reportedly taken over the role of America’s first openly gay politician, Harvey Milk, in a biographical movie about his life.

According to The Hollywood Reporter, Matt Damon is currently in talks to play Dan White, Milk’s assassin, in the movie which is to be helmed by Gus Van Sant, whose work credits include "My Own Private Idaho," "Drugstore Cowboy" and "Only Cowgirls Get The Blues." Shooting is set to kick off in San Francisco the upcoming winter if all distribution work is finalized. The uncertain start date may affect Damon's participation as Milk's killer.

Producer Michael London and his Groundswell Prods. are financing the film, set to be produced by Bruce Cohen and Dan Jinks from a script by Dustin Lance Black ("Big Love").

"X-Men" director Bryan Singer is also believed to be planning a rival project on Milk's life in collaboration with "The Usual Suspects" writer Christopher McQuarrie, but has been delayed by his commitment to directing a sequel to "Superman Returns."

Milk was the first openly gay official to be elected to the San Francisco Board of Supervisors before being shot dead in San Francisco alongside the city’s Mayor George Mascone in 1978. White, a disgruntled former Supervisor, was sentenced to seven years behind bars but committed suicide in 1985. His short sentence caused an uprising of the San Francisco gay community in which 160 people were injured.

On an audio tape released after Milk's death, he seemed to anticipate the event. "If a bullet should enter my brain, let that bullet destroy every closet door," he can be heard as saying. Milk has since become adopted as a martyr by the gay rights movement in America. A bust was recently put on permanent display in San Francisco City Hall.