oh, his Queen back home has a definite interest in punishing him. There has been a lot of violence in her kingdom towards the other race...and as some of her advisers and best friends are part of that race (including the MC) she wants the kingdom to be safe for them. She's executed quite a few already for murder, so she won't hesitate to give this guy what's coming to him.

And since I do intend a meeting between the two monarchs, they can work this out between them.