Unfortunately the only way of getting your coins back is to link the addresses to a real identity.
This can happen through law enforcement agencies and their IP's or through any other sources.
Without this, the chances are pretty low.
Regarding the tracing, did you check whether the address which 'might be part' of the scammers one does have transactions related to the known scammer addresses ?
As BTC is complety SAFE and ANONYMOUS, there is no way to get one back, when handed over.
Bitcoin is NOT anonymous, not at all. BTC is pseudonymous.
Addresses can be linked together building entities with traces in between of them. Proper chain analysis can definitely gain knowledge regarding transactions happening on the blockchain.