The Broken Frame Mike Hammer : Season 1 Episode 22

A convict on death row confesses to a murder that another man was executed for three years earlier and threatens to supply proof after he dies on the electric chair. Mike doesn't pay much attention to man's story until the gun used in the crime is produced. Captain Chambers is worried that an innocent man lost his life based on shoddy police work, but Hammer is convinced that the grocery store robber had a partner and sets out to prove it.