My friend got scammed — looking for OSINT advice

My friend buys and sells USDT in a developing country. He was recently scammed by someone on Facebook using a fake profile that appeared to have been active for several months.

The scammer sent him a fake receipt claiming that money had been deposited at a post office. My friend trusted the receipt and sent him the USDT. Later, when my friend went to the post office, he discovered that the receipt had been falsified and that no money had actually been deposited. By then, the Facebook profile had been deleted.

I know my friend acted too quickly and should have verified the payment before sending the USDT.

I'm now trying to gather as much information as possible about the scammer and, hopefully, provide useful evidence to the authorities.

So far, we have:

Screenshots of the QR codes / crypto deposit addresses used for Bitget and Binance

The blockchain transaction information

A recording of the scammer's voice

Screenshots of the Facebook conversation

The fake name used by the scammer

The fake post-office receipt

I'm looking for advice from people experienced with OSINT and crypto investigations.

What tools, techniques, or investigative methods would you recommend for connecting these pieces of information and potentially identifying additional publicly available information about the scammer?

Any advice or recommended tools would be greatly appreciated.