"I had to express the worst time in her life and the moment when she received the worst information of her life," Jolie, 31, tells Glamour magazine in its June issue, on newsstands May 8. "It became the worst acting day of my life — and really, the hardest thing I've ever done."
"A Mighty Heart," directed by Michael Winterbottom, is based on Pearl's account of her husband's abduction and murder in Pakistan in 2002 while researching a story on Islamic militancy.
Dan Futterman plays Daniel Pearl. The movie, to be released by Viacom Inc.'s Paramount Vantage, will be shown at the Cannes Film Festival in May.
"You know, Mariane, you're somebody who has every right to have a lot of anger," Jolie tells Pearl, who was also interviewed for the Glamour article. "And the fact that you take a deep breath and stand up with a very clear voice of tolerance and dialogue — that's why I wanted to do the film."
Photos: Angelina Films "A Mighty Heart"
"Well, that kind of self-control hasn't been easy for me," replies Pearl, who was five months pregnant with her son, Adam, when she learned of her husband's fate.
Her first reaction was to grab "an AK-47 from one of the guards. ... If they had brought a person who was guilty (of Pearl's murder) to the house, I would have shot him," she says.
"But then I would have destroyed everything Danny believed in, and everything we did as a couple — and I couldn't do that. Putting that gun down was my biggest act of courage."
Photos: Angelina Jolie At Tribeca
Pearl says she wanted to meet Jolie after reading an interview with the actress a few years ago.
"I thought, 'This woman could be my friend.' I'd never experienced anything like that before in my life. It was something in her tone, in the answers that she gave. I felt also that Maddox and Adam (then both about 3) could be good friends. So I sent her a note saying, 'Do you want to have a play date?' "
Says Jolie: "Her instincts were right — we did have so much in common. And all the kids are great friends now. Zahara is madly in love with Adam."