G-Men Never Forget Chapter 06: Marked Evidence

G-Men Never Forget is a 1948 Republic movie serial with 12 chapters.

Escaped criminal Victor Murkland (Roy Barcroft) kidnaps the police commissioner and, with the aid of plastic surgery, takes his place. Federal Agent Ted O'Hara (Clayton Moore) is called in to try to stop the wave of crime initiated by Murkland, not knowing that Murkland is posing as the police commissioner and is aware of O'Haras' every move. The real commissioner is being held captive in a mental hospital run by Dr. Benson (Stanley Price). O'Hara is aided by the beautiful Sgt. Francis Blake (Ramsay Ames). Murkland's gang threatens to destroy a major tunnel being built underneath a channel, and blackmails the builder into paying him protection money.

Cast:
Clayton Moore as Agent Ted O'Hara
Roy Barcroft as Victor Murkland/Commissioner Angus Cameron
Ramsay Ames as Frances Blake
Stanley Price as 'Doc' Benson

text from wikipedia