This was reportedly released in the U.S. in the 70's in a badly cut form and billed as a horror film.
It is clearly a CRIME film, one that focuses first on the malefactors (led by a crazed, sociopathic Tomas Milian) and only second on the pursuing detective (one mightily p****d-off Henry Silva). The version I saw, supposedly "uncut," certainly did not leave me bored. It's trashy, over the top and exploitative, expressing much the politics of a "Dirty Harry" rip-off with its emasculated cop driven to vigilante tactics and its sleazy anti-hero (Milian) who will literally stop at NOTHING, not even remorseless, cold-blooded murder, just to steal a few bucks out of a cigarette machine. But it didn't leave me bored.
Milian's riveting (as usual) performance--many complain that he exaggerates too much but I feel they're missing the point--suffers greatly due to the bad English dubbing. This is quite frustrating, since Milian speaks English and could have done it himself. The excellent Morricone score also suffers, since the music suddenly gets lowered or stops altogether every time a character speaks. But these are faults, I'm sure, of the English language version and not of the film itself.
The film itself, taken on its own terms, is entertaining as hell. Especially if you think Hell might be entertaining. Milian's character, a small-time hood named Sacchi who is determined to make it big by kidnapping a rich guy's daughter, is on a hell-bent mission. He doesn't care who he kills, tortures or rapes as long as he doesn't leave witnesses. When he's not killing, torturing and raping, he's committing brazen acts such as following the cops who are supposed to be following him and going to the police station to report his own crimes.
It's a bloody crime film that never lets up. It's set in a desperate, anarchic urban landscape where Grandma and Grandpa sell machine guns. Morricone's score adds a whole ominous dimension; the music in the opening credits just says, "Ugly things are about to happen." And they do. Just look for a version with subtitles, if you don't speak Italian.
Quentin Tarantino's mother was blowing his nose, damn straight.