The Two Mrs. Carrolls(1947)

Struggling artist Geoffrey Carroll meets Sally while on holiday in the country. A romance develops, but he doesn't tell her he's already married. Suffering from mental illness, Geoffrey returns home where he paints an impression of his wife as the angel of death and then promptly poisons her. He marries Sally but after a while he finds a strange urge to paint her as the angel of death too and history seems about to repeat itself.