What the hell you need a lawyer for? Since his IP is in Kansas, any one of you US citizens should be able to complain directly to police, and let them do the leg work. Bit trickier for us Brit's though.
lol! "Hello Kansas police? Yeah see this guy stole my Dogecoin..."
ok, laugh, I don't know abour your laws, I assume they are not too different to ours, and over here we have a specific offence called 'obtaining goods and services by deception', he has clearly obtained the services of our miners by deception, and if he was in UK I would be down the local police station in a heartbeat, and they would be obliged to investigate!