If this guy is always on a VPN, running an "invisible" image off a hosted site to get the IP connection won't work. But, if they happen to be a little careless, then depending on the way you can contact him you could glean something from this.
If the hacker always use vpn then there might have low chance to caught him, but still it should be reported on FBI. Less is better than never. And if the person become careless for a while then there will be high chance to catch the hacker.