yes the tattoo will sign him for life...
...little bit mafia-methods , but he will think twice in the future, before go and steal the next bike ...
and i think it could be more near by you, as you think... did they stole only your kx500 or more of your inventory?
5 years ago had my local kawasaki-dealer these kind of night-visitors. 6 bikes and some new parts and clothes were stolen.. and at least , it would be found only 15 kilometers away in a barn...