John Cusack on Taking On a Serial Killer

John Cusack has taken on a few dark roles in his film career, but embodying a serial killer in The Frozen Ground was something he hesitated to do.

As Cusack recalls in ETonline's exclusive sneak peek at a behind-the-scenes clip from the Frozen Ground Blu-ray/DVD, his decision to play the role of Alaskan serial killer Robert Hansen was a conflicted selection process.

PICS: Exclusive Photos: 'The Frozen Ground'

"I was about the age of Cindy Paulson (escaped victim); I was about 17 or 18 back then, so I was the age of one of victims," Cusack said. "I remember hearing a story of a guy...[who] went out and hunted people and did these things. I sort of pushed it away 'cause I thought it would have to be the right circumstance to do it 'cause it's a very dark subject matter."

Despite the numerous atrocities that the serial killer commits in the film, Cusack and director Scott Walker worked countless hours to ensure that his portrayal wasn't sensationalized and was more reflective of a real serial killer.

"We would spend hours discussing each scene and each line and how to deliver those lines so that he doesn't seem to be over-the-top and suddenly something which isn't true to how a real serial killer is," Walker said.

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Although Cusack possesses an uncanny resemblance to Robert Hansen, who is now 74 years old and serving a 461-year prison sentence, his co-star Nicolas Cage was in contention to play the antagonist but opted to allow him to field the role.

"The twist is that most people automatically assume that I'm going to play the serial killer," revealed Cage, who plays the fictional "Sgt. Jack Halcombe" based on Alaskan detective Glenn Flothe, "and I could. I understand where to go with that but I wanted to see what John Cusack would do with that."

Watch the exclusive bonus feature above and grab your copy of The Frozen Ground beginning tomorrow, October 1.