The Sinners(1976)

Overview:

Actress Sanaa Kamel is found murdered on her bed, and an investigation starts, taking into account everyone of the guests she hosted at her apartment the night she was killed: her jealous fiancé, a school instructor, a corrupt market manager, one of Sanaa's friends who works as a contractor, and a stud who was Sanaa's secret lover. As the investigation progresses, all the conclusions about the characters are always under question.