Double Jeopardy (1955)

Emmett Devery is being blackmailed by his former partner, Sam Baggott, who served a prison term years before on a shady business deal. Devery's daughter, Barbara, and his attorney, Marc Hill, in love with Barbara, know nothing about the situation. Baggott applies more blackmail-pressure and is killed by Jeff Calder, the boyfriend of cheating-wife Marge Baggott, who tried to double-cross Marge by getting the money himself. The police investigation of Baggott's murder leads to Devery, who admits that Baggott was blackmailing him but denies killing the extortionist. Hill and Barbara begin their own investigation.