This is probably the best of the many, many "polizieschi" flicks director Stelvio Massi directed in the 70's. It has a nice tight plot (unlike more meandering stuff like "Convoy Busters") and it benefits from strong acting by Tomas Milan, Ray Lovelock, and (especially) Gaston Moschin. Milan plays a renegade cop after a group of criminals who murdered his wife five years earlier. While posing as "polizieschi" filmmakers(!), the gang pulls a daring daylight robbery that leaves a policeman dead. They then try to flee Italy dressed as machine-gun toting priests(!!). Moschine plays "the Marseillese" the treacherous, cigar-chomping leader of the group. Lovelock plays a political radical and intellectual who works as the gang's wheel-man. Stefania Cassini plays the rather irritating bimbo girlfriend.
Massi does a pretty good job keeping the plot together for a change. He splits the screen time between the bickering, treacherous gang and the relentless cop. This is far from Milan's best role, but he's pretty decent. Lovelock plays an interesting character who should have had more screen time. Cassini, very atypically, keeps her clothes on for some reason (although there's plenty of gratuitous nudity involving a porno club and a scene where the gang holds an entire family hostage, apparently just so they can feel up the mini-skirted teenage daughter and rip her blouse open a couple times). Cassini is a good actress, but her character is pretty annoying and really serves no function. I was very impressed though with Moschin, who I've only seen previously in the sex comedy "Erotomania". He is a far more effective presence in this genre than in comedies. (Although his final face-off with Milan is kind of disappointing).
In any event, this is worth watching, especially if you like the Italian crime thriller genre.