Born to Kill (1947)

Drifter Sam Wilde (Lawrence Tierney) murders a Reno, Nev., boardinghouse owner and her boyfriend in a fit of jealousy. Tenant Helen Brent (Claire Trevor) discovers the bodies, but instead of reporting the crime, she leaves for San Francisco as planned to return to her wealthy fiancé. On the same train, Sam flirts with Helen, then tracks her to her half-sister's house, where he continues to pursue her. Although Helen suspects Sam is a murderer, she inexplicably protects him from an investigator.