'Servo Suo' aka 'Your Honor' (1973) – Romano Scavolini.

A solitary, down on his luck school teacher (Nick Avram) is kidnapped by gangsters and coerced/indoctrinated to do a hit in Romano 'Nightmare's in a Damaged Brain' Scavolini's enjoyably low-key, downbeat Euro-crime gem. The fine cast does much to boost the pulpy material, composer Carlo Esposito's hepcat jazzy lounge funk is another key element, and the cult director keeps the pace lively enough. Made during an era when steely male protagonists advertised their Alpha status by aggressive day drinking, studied misanthropy, wiry thatches of exposed chest hair, an unyielding 'fists first' policy, and slept with implausibly beauteous prostitutes whose debauched life only barely tarnished their inviolate hearts of gold. 

 “He doesn't have any friends, he's a stray dog!”