The best bet is to report each of these accounts to Facebook as either fake or scam/spam each and every time they show up. Facebook usually shuts these accounts down quickly.

we can report them. to facebook which will take time usually. or we could easily report them to the f.b.i. or we could take action into our own hands.
one of us on this page might even know how to track a IP address. all we need is the real name of the person, than we could take the person down.

You could report them to the FBI, true, but they will most likely let Facebook handle it. Theoretically, you could track an IP address, but since the request is coming directly through Facebook, you probably will not be given the address, as they will only give it out to law enforcement. They can then ban by IP address, but even that may not work, as the person  may not be using a dedicated IP.

there has to be some other way to take this person down though? facebook will take the account down, yes. but that wont stop the person from attacking other people by making  more emails and accounts. if someone is able to get the legit name of the attacker i can do a background check on them through internet. this person is experienced as we can tell allready.

You might try filing with Internet crimes..

https://www.ic3.gov/default.aspx