Sam Rockwell (CRAIG ROBERTSON, QMI Agency photo)

Sam Rockwell was cast as real-life wrongfully convicted murderer Kenny Waters in Conviction just a month before shooting began on the drama.

Needless to say, the slight 41-year-old California native had no time to beef up to play Waters, a considerably larger man from Ayer, Mass.

"I tried to bulk up a little bit but that kind of weight, to put that on so quickly, it wouldn't be healthy and it wouldn't be practical," Rockwell told the Sun in Toronto last month for TIFF, where Conviction premiered. The film opens Friday in Toronto.

"It would have been great to have him skinny in the beginning and gain weight towards the end but we just didn't have that luxury. It was really a low-budget independent film."

Once cast, Rockwell, Hilary Swank (who plays Kenny's sister Betty Anne Waters) and director Tony Goldwyn got in a car to visit the real-life Betty Anne -- who put herself through high school, college and law school over 18 years to get him freed -- in Rhode Island.

Tragically, Kenny died six months after he was freed from prison in 2001 at the age of 47 after falling from a wall and fracturing his skull.

"We drank some delicious beer," joked Rockwell at a press conference, recalling his time with the Waters clan.

"No, it's always a responsibility I think when you're playing a real person, an extra thing, like an accent or something. It's a responsibility you have to take on but fun. But you do feel like you owe this to this real person to represent them, their passion."

Rockwell, a versatile actor best known for offbeat portrayals in such movies as Lawn Dogs, Confessions of a Dangerous Mind and Moon, also had access to stills and audio of Kenny plus the letters he wrote from prison.

"It's just like more baggage and you got make the baggage look lighter, not like you're impersonating," he said of playing a real person versus a fictional character.

"I think we just have an affinity for this film, all the actors and Tony, and we just feel strongly about this movie. It was a lot of blood, tears, and sweat involved in making the movie, so I think it's a lot invested."

Waters, who spent a lot of time on the set as well, said it wasn't until she saw the finished version that she appreciated Rockwell's portrayal of Kenny.

"I didn't know how it was going to turn out in the end because (Sam) doesn't look like my brother but when I saw the movie it was unbelievably my brother," she told reporters. "I felt my brother. I felt like he got Kenny. He got his personality. The things that he said, his actions, he totally nailed Kenny. He really did."

For her part, Swank praised Rockwell's acting skills, particularly in their prison scenes together.

"Sam is a great improviser and he will just come up with some of the funniest stuff that will have me in tears," she told reporters. "I imagine that's what Kenny and Betty Anne were like."

jane.stevenson@sunmedia.ca

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