The 7th Commandment (1961)

A man and his girlfriend driving in their car have an accident. The man gets amnesia and wanders away from the accident. He is taken in by a traveling preacher, and several years later returns to his hometown as the Rev. Tad Morgan, still unaware of his previous life there. His girlfriend, who was injured in the accident and is now an ex-convict living with her crook boyfriend in a sleazy apartment, decides to take her revenge on the now-respectable preacher.