JOHNNY Depp has revealed he felt "a tremendous amount of responsibility" in portraying real-life Irish-American gangster James "Whitey" Bulger.
Notorious Boston mob boss Bulger, who is in his eighties, is serving life in a Florida jail after he was convicted in 2013 of 11 murders.
He ran Boston's Irish-American Winter Hill crime gang in the 1970s and 1980s and had links to the IRA, allegedly helping to smuggle arms to the republican paramilitaries.
Depp, star of films including Edward Scissorhands and Sweeney Todd, admitted he felt some pressure to do the role justice as the film premiered at the Toronto International Film Festival.
"When you're playing a fictional character, there's room for... you can kind of stretch it out into strange places. When you're playing someone who either existed or exists, there's a tremendous amount of responsibility, at least for me," the Golden Globe-winning actor said.
Depp plays Bulger in Black Mass, which also stars Benedict Cumberbatch, Joel Edgerton and Kevin Bacon.
The film, directed by Scott Cooper, is based on Dick Lehr and Gerard O'Neill's 2001 book Black Mass: The True Story Of An Unholy Alliance Between The FBI And The Irish Mob.
The 52-year-old actor said Bulger declined to meet him.
"The first thing I did, I contacted Bulger's lawyer Jay Carney to request the opportunity to meet James Bulger, to hear his take, certainly... and to be able to study him," he said.
"About a week after I made the request, I got a message from Mr Carney that said, 'Jimmy respectfully declines as he is, as you can imagine, not a great fan of the book', nor any of the books. He would never put his client into any sort of weird situation but he was very helpful with regards to the heart of Bulger, the heart of the man."
Depp - who arrived with wife Amber Heard at the film's Canadian premiere yesterday - said he wanted to show a "human" side to Bulger.
He said: "My intention was not to go out and create someone who is evil, because I don't think any of us wake up in the morning, shave and brush our teeth and think, 'I'm so evil, I'm so horrible'.
"I approached James Bulger as a human being who is multi-faceted and had a side to him that was human, loving and all that. And then he's in this business - certain businesses out there, where the language of that work is violence, so that's the only way I could approach it."
Black Mass opens in the UK on November 27.
