Stranger On The Third Floor (1940) DVD

A young reporter, Mike Ward (John McGuire) stumbled upon a murder victim and identifies a nervous cabbie (Elisha Cook Jr) as the person he saw previously arguing with the dead man. On the strength of Mike's testimony, the cabbie is convicted. Mike however is haunted by the the knowledge that he may have sent an innocent man to the electric chair for murder and that means the real maniac is still on the loose! These doubts increase when he runs into a creepy psycho played by Peter Lorre. Things take a turn for the worse when another murder is committed, a murder which may point, ironically enough, back to Mike....