The Great Impostor (1960)

Synopsis
The Great Impostor is the true story of chameleonlike Canadian Ferdinand Waldo DeMara Jr., well-played by Tony Curtis. Unable to decide what he wants to do with his life, DeMara goes about pretending to be other people, hoping to eventually "find himself." He poses as a Harvard professor, a Trappist monk, a prison warden, and a navy physician, and manages each time to get away with the artifice. The film wavers uncertainly between tense drama and frothy comedy, with comedy finally winning out. Karl Malden co-stars as Father Devlin, the young DeMara's spiritual advisor, while Joan Blackman is the nominal (and hardly visible) heroine. The real Ferdinand DeMara (if indeed there was a real Ferdinand DeMara) can be seen in a supporting role in the 1960 melodrama The Hypnotic Eye. ~ Hal Erickson, All Movie Guide