The Bird with the Crystal Plumage (1970)
An American writer living in Rome witnesses an attempted murder that is connected to an ongoing killing spree in the city, and conducts his own investigation despite himself and his girlfriend being targeted by the killer. based on novel or book, psychopath, painting, murder, whodunit, maniac, knifing, killer, art gallery, voyeurism, stutterer, black gloves, giallo
ETC.
