Deep Red
One of Dario Argento's most famous Italian horror films, many of which play with gender, sexuality, and social critique, Deep Red has a gay supporting character who is wrongly assumed to be guilty because of his sexuality.
An English pianist living in Rome witnesses the brutal murder of his neighbor, a psychic. With the help of a tenacious young reporter he tries to discover the killer using very unconventional methods, and the two are soon drawn into a shocking web of dementia and violence.