its a horrible experience which makes you feel really impotent.
I believe they have pills for that now.
Reply back and give him an offer to return. Bring friends with a bat and beat out of him !
No cops needed ...
Slime balls need to be dealt with in a non sensible way.
One, if he does that, he'll end up sharing a cell with the thief.
Two, from that e-mail, it sounds like the guy who currently has the phone bought it from the thief on Craigslist and has spent a few hundred bucks on a useless phone. He is not the guy who needs the piss beaten out of him. Maybe trying to sell it back to the OP to recoup his losses isn't the smartest idea, but someone's going to be stuck with the loss and it's either the OP or the sender.