The Great Owl’s review published on Letterboxd :
Detective Lt. Barney Nolan (Edmond O'Brien) is a bad, bad crooked cop. In the opening scene of Shield for Murder, he kills a bookie in order to steal $25,000. All seems to go well for Nolan, as he promises his girlfriend, played by Marla English, that they will get married and live in a beautiful new house. When a deaf and dumb man comes forth and reveals that he witnessed the killing of the bookie, however, Nolan is compelled to cover his tracks at any cost. Shootings and mayhem ensue.
Edmond O'Brien is one of my favorite film noir actors, having starred in D.O.A., White Heat, The Hitch-Hiker, The Shanghai Story, Man in the Dark, A Double Life, and The Killers, and he is at his uptight best in this movie. John Agar, a supporting actor of westerns like She Wore a Yellow Ribbon, is excellent as Nolan's friend on the police force. Carolyn Jones, who played Morticia in The Addams Family, is fun to watch as a sleazy blonde who tried to hit on Nolan at a bar. Finally, country and western star Claude Akins stars as a hostile private detective of sorts who is out to find the bookie's money.