The Bloodstained Butterfly is the odd giallo where the police seem dedicated to their job. Although it boasts the elaborate murders and cast of red herrings one expects from the genre, it also surprises by spending at least as much time on police procedure, forensic science, and courtroom maneuvering.
Alan is a handsome aristocrat who enjoys velvet jackets, cravats, and murdering strippers. He marries a woman in hopes she will curb his homicidal outbursts, and his creepy estate is soon haunted by the ghost of his former wife.
When it came time for Mario Bava to turn in his version of a Hitchcock movie, he picked up on that underlying current of malicious giddiness and ratcheted it up. In Blood and Black Lace, Bava is a peasant let loose to demolish a nobleman’s home.