Having made the big mistake of turning down Dirty Harry three years previously, this was Wayne's belated contribution to the cop movie bandwagon.
Getting to the bottom of a drugs and corruption conspiracy, he smashes one villain's head into a bathroom mirror and sorts out a car full of others with a submachine gun.
Strangely, it's a film without a reputation, but it's scripted and performed at least as well as any of the Dirty Harry sequels and the fact that Wayne, who was well into his sixties at the time (obvious toupee, open necked shirt, slightly leathery orange glow) is far too old only adds to its charm.