Interesting. He used the same bitcoin address in the threat he sent me too. When one of us pays up, how is he going to know who to protect?

The "from" part would be different. He'd ask you to sign a bitcoin message.
That was my point about the address not being in the blockchain. Sure, it might be in cold storage, but if the gangster is using a unused address for multiple targets then that suggests he's new to this (and possibly not good at it).