So Sweet, So Dead (1972)

aka’s: Rivelazioni Di Un Maniaco Sessuale Al Capo Della Squadra Mobile/Bad Girls/Confessions Of A Sex Maniac/Revelations Of A Sex Maniac To The Head Of The Criminal Investigation Division/So Naked, So Dead/
The Slasher Is The Sex Maniac

Someone is butchering the unfaithful wives of an Italian town’s jet-set. The killer spies on adulterous couples, snapping incriminating photographs of flashed breasts and sweaty embraces, which are subsequently left for the police to find (but always with the man’s features scratched out) next to the bloody bodies of the slaughtered women. Inspector Capuana (Farley Granger) is frustrated by his lack of progress after finding the first body, that of a General’s wife, naked and slashed in a hotel bedroom. He resorts to rounding up the usual suspects, the town’s “undesirables” – prostitutes, homosexuals and hippies – before realizing that the killer is likely to be found among the town’s well-to-do. Also stars Sylva Koscina.