If the scammers make a mistake and sent your coins to addresses and wallets associated with centralized services where they verified their identity, you can request to have those accounts frozen and the perpetrators identified. You seem to have the necessary police report and supporting documents from law enforcement. However, if the thieves are experienced enough, they won't make such mistakes. The coins that they converted to monero are pretty much gone. Chances that you will get them back are very small.
If they run their own nodes, avoid KYC services, use DEXs or stolen CEX accounts, reside in jurisdictions out of reach of US law enforcement, and don't send the stolen coins to any addresses that could identify them, there isn't much that anyone can do.
Have you tried to contact a blockchain analysis firm yourself to see what they say?
Perhaps people like
ZachXBT who investigates crypto thefts can also be of help.