Police ?
I do not know if they could find this developer even
he is from another country
You probably also live in another country
and probably uses a VPN
I'm not a proponent of this kind of solutions to go to the police
I think that it should be controlled in some way
and the developer's home address should be known
or the address of his company
then you could be half to such a motherfucker
and he just wants to fuck him in the mouth
tie up with barbed wire and pull behind the car for example
then he would learn that he does not do it