Watch Sin by Murder Full Movie Free Online 123Movies. On the night of their tenth anniversary, corporate lawyer Michael Barnes' wife is brutally murdered. Labelled the prime suspect by Detectives Jack Burns and Amy Cobb, Barnes must try to clear his name before it's too late... Along the way, Barnes' closest friends begin to show their true colors, and with no one left to trust, he finds himself with nothing to lose as he's faced with the toughest decision of his life.