I'm a little surprised to find out its such a polarizing film, it seems one either loves it or really dislikes it. But thats what makes art so much fun to dissect. Interesting to note, Nicolas Winding Refn (Drive, Valhalla Rising) says its his favorite Italian film of all time.
It's great, and I believe thats Tomas doing his own dub in Italian which was rare for him in the 70s. One thing tho, its not really as poliziesco as it is advertised, its more like an exploitation-thriller. Similar to Mad Dog Killer in that way.