Spasmo (1974)

On a beach a young couple happens on what appears to be a corpse, but upon further inspection, they see that the woman is still alive.

I corpi presentano tracce di violenza carnale (1973)

Someone is strangling coeds in Perugia, and the only clue is that the killer owns a red and black scarf

Psycho-Circus (1966)

A circus becomes the location for stolen loot and murder.

[aka Circus of Fear]