The 63rd Venice Film Festival has started with the world premiere of The Black Dahlia, starring Scarlett Johansson.
Scarlett Johansson lines up with the writer, director and the rest of the cast
The movie is among 21 films up for the Golden Lion award, which was won last year by Brokeback Mountain.
Dame Helen Mirren plays the title role in main British contender The Queen, a provocative look at the Royal Family.
Rachel Weisz and Kenneth Branagh are among the stars expected to attend the 11-day event.
Adapted from the novel by James Ellroy, The Black Dahlia is based on the notorious unsolved murder of aspiring actress Elizabeth Short in 1940s Los Angeles.
GOLDEN LION WINNERS
2005 - Brokeback Mountain
2004 - Vera Drake
2003 - The Return
2002 - The Magdalene Sisters
2001 - Monsoon Wedding
Brian De Palma directs a cast that also includes Josh Hartnett, Aaron Eckhart and two-time Oscar winner Hilary Swank.
At a press conference for the film, Johansson drew comparisons to the media interest in the Black Dahlia case to that surrounding the murder of six-year-old JonBenet Ramsey.
"People distract themselves with those type of news stories so as not to pay attention to their own depression," she said.
"Generally, when there are periods of depression in a country, people distract themselves oftentimes with scandal."
Ellroy said his book was set during "an obsessive period of my own life history" drawing from his own mother's death in 1958.
The Bafta-winning actress arrived in Venice on Tuesday
"The Black Dahlia murder was the first media-manipulated murder in American history. I got lucky with my parentage - I got hatched in LA, the film noir epicentre," he said.
"Twice in my 27-year novel career I've been lucky with film adaptations. The first was LA Confidential, and now The Black Dahlia."
Together with The Queen, which dramatises the Royal Family's response to the death of Diana, Princess of Wales in 1997, The Black Dahlia is one of several films in this year's competition line-up based on true events.
Others include Sharon Stone in Bobby, which revisits the assassination of US Senator Robert F Kennedy in 1968, and Hollywoodland, a drama based on the mysterious death of Superman actor George Reeves, played by Ben Affleck.
Dame Helen Mirren plays Queen Elizabeth II
Screening outside the main competition is Infamous, the second film in the space of a year about US writer Truman Capote and his relationship with killer Perry Smith.
New James Bond Daniel Craig plays Smith, the subject of Capote's book In Cold Blood, while British actor Toby Jones portrays the author.
Weisz appears in The Fountain, a time-hopping romance directed by her partner Darren Aronofsky, while Branagh will be screening his film version of Mozart's opera The Magic Flute out of competition.
Other British actors with films at the festival include Clive Owen and Sir Michael Caine, stars of the futuristic drama Children of Men.
Director David Lynch, who will be screening his latest work Inland Empire during the festival, will receive a lifetime achievement award.