Cornered

"A pair of professional thieves discover that their accomplice, Mary Brennan, is a dead-ringer for wealthy heiress Margaret Waring. They wait until Margaret is absent from the house, then place Mary there to make their heist easier. Unfortunately, Margaret returns before they've finished the job and gets shot. When the police get there, both women claim to be Margaret Waring and accuse the other of being the thief--and they look so much alike that no one can tell the difference."