He's been declared dead by both Israel and Hamas.

How about the Hamas leaders living in Turkey? They were just kicked out of Qatar, and being in (semi-)European Turkey should be easier to arrest, no? Remember, these Hamas leaders in Turkey actually, really, call for explicit genocide - and carry out their actions.

In law we generally prosecute those who are responsible according to the law. Not those who happen to be available so that we have someone to make pay.

Not saying that there are undoubtedly more “bad people” than just him. But that’s not how law works.