>> for murder. >> and just when you think this case couldn't get any stranger, another twist. an ex-con came to spezi and in return for a few euros gave him a white-hot tip. the source claimed that carlo had taken him to one of his hideaways on the grounds of this centuries-old villa, and what he had seen inside might crack the monster case once and for all. >> he told me that he saw in his house the gun and in a little armoire six metallic boxes. >> the gun, and in an armoire, six boxes matching the number of women who had been mutilated by the monster. tantalizing, and if true, proof that carlo was the killer. did you believe it? >> well, yes. >> spezi just about had a heart attack. he was telling me this. i said, mario, this sounds too good to be true. >> it's a renaissance villa. >> but preston was intrigued enough that he asked spezi to