Cape Town - Zac Efron takes on the role of Ted Bundy in the film, Extremely Wicked, Shockingly Evil and Vile, which opens in cinemas on Friday, 3 May.
The film chronicles of the crimes of Ted Bundy, from the perspective of his long-time girlfriend, Elizabeth Kloepfer (Lily Collins), who refused to believe the truth about him for years.
Director Joe Berlinger says it was important for him to cast someone likeable who some members of the public believe "can do no wrong".
(See video above)
Speaking at the premiere of the movie Zac revealed that he did not use too much method acting for this role to protect himself.
"I was able to compartmentalise and leave him on set, in the jail cell, most days."