what do you think of this theory? >> it's completely crazy. it's completely crazy. >> spezi developed his own very different theory based on something he says he was told by a high-ranking member of the carabinieri, the italian federal police. >> they tell me to a journalist who is writing about the monster, they told this new story very interesting. >> the carabinieri had withdrawn from the case years before, reportedly outraged at the way it was being managed by local investigators. >> but obsession is obsession. they continued a secret investigation into the sardinian connection to see if they could figure out who the monster of florence was. >> the unofficial investigation had led to a suspect. he was the son of one of the sardinians involved in the '68 murder. so he could have gotten hold of the gun. the key to the whole mystery. >> this is the real, real problem of the case of the monster of florence. >> who has the gun and how they