Inspector Betti is a fictional character created by Marino Girolami and Vincenzo Mannino and portrayed by Maurizio Merli; he appeared in the "Inspector trilogy," comprising the films "Violent Rome" (1975), "Violent Naples" (1976), and "A Special Cop in Action" (1976). The sequel/spin-off "Weapons of Death" was released in 1977, featuring Inspector Belli (played by Leonard Mann) as Betti's replacement. Gennarino—a child character who had already appeared in "Violent Naples" —also makes an appearance.

Napoli violenta
“He's the dirtiest law-enforcer ever to hit the streets...”
Inspector Betti (Maurizio Merli) is transferred to Naples and immediately after his arrival receives a warm welcome from The Commandante (Barry Sullivan), the city's crime lord. Betti then goes on a personal mission against corruption and organized crime, and tries to force the syndicate out of town with any means necessary.