If Giallo is an allegoric illustration of Italy's dark years, then Poliziesco, this other typical 1970s Italian genre cinema, is their very realistic, day-to-day report.
In Giallo, violence has no face as it can take anybody's identity.
In Poliziesco, criminals are all clearly identified: street punks, small-time thieves, dangerous gangsters, corrupted policemen or cynical politicians, all of them drawing the scary portrait of a seriously ill Italian society. Sometimes a simplistic portrait, yet sketched up in an ever efficient and graphic manner.
Like in "Il Cittadino si Rebella" (Street Law - Enzo G. Castellari, 1974), one of the highlights of the genre. From the first to the last second, this movie, based on the revenge of a banal citizen against the gangsters who brutally kidnapped him during a bank hold-up, is a breathless sequence of action scenes which have clearly been used as Tarantino or John Woo's back catalogue for their own films.
One amazing scene. Carlo Antonelli (Franco Nero) is running for his life, chased by a gangster's Ford Mustang. This scene is under influence: it's a western scene, with the Mustang moving like an infuriated horse. It's also a tribute to Hitchcock's "North by Northwest", with its strange similarity between Franco Nero and Cary Grant's run to escape a machine.
Above all, this scene is a ballet, a deadly choregraphy between a man and a machine, shot like contemporary dance, from sophisticated angles, with the camera accompanying the agressive and desperate movements of the car and its prey, in slow motion to stress their beauty, in close-ups to enhance the brutal feeling of fear.
The uglier the reality, the more beautiful its representation.
"Il Cittadino si Rebella" is a very good introduction to Poliziesco. Its score, by Guido & Maurizio de Angelis, is inspired by early 70s American cop movies and has some definitive Blaxploitation influences.
More about this cinema genre on this great site: Pollanet Squad (in Italian).