I have no idea if the OP is who he says he is. The telephone number and email address appear to be associated with the person who the OP says he is. This person appears to work for the FDA, and I am not sure why the FDA would be investigating anything to do with bitcoin, or even most crimes (the only crimes they investigate are
those related to products the FDA regulates).
The person the OP claims to be does not appear to work in the law enforcement side of the FDA. I think there is a chance the OP is actually trying to get people to harass the person he is claiming to be by posting his contact information.
There are a number of private entities that I believe contract with government law enforcement agencies that help with the types of problems the OP claims to need help investigating. One of the well-known companies is
chainanalysis.
My best guess -
The email and bitcointalk account are from the real owner, but his email was somehow compromised, so the imposter can reset the details and gain access to his bitcointalk account.
The phone number is not from the real owner and was registered with a fake name by the imposter, that's why when people do reverse search, it shows as the real owner's name.
So no matter people try to contact the person via email or phone call, it will all ended up answered by the imposter.
OP said he will share his personal ID via video call, but it's impossible to do a video call via email or a regular phone call.
So my best guess is that the person will make up a story and says it's a top secret video call so you need to pay a certain fee to access it, blah blah blah.