Invisible Strangler

This ridiculous film concerns a young lad who strangles his mother when she tells him that she wishes she had aborted him. Locked away in a mental hospital, he studies books on the occult (what kind of mental hospital would let a disturbed inmate have books like this is a question left unanswered) until he learns an ancient Buddhist technique for becoming invisible. He then escapes his rubber-padded room and goes on a murder spree, under cover of invisibility strangling his mother's old friends in their posh homes. These scenes are ludicrous--women, seemingly all alone, suddenly start choking, their eyes rolling up in their heads. The detective assigned to the case...