If the location where those crimes happened would be in a country that signed up to the international criminal court (treaty of Rome), it could actually work, eg Venezuela or Caribbean countries. It would in any case greatly hamper Petey’s freedom of travel across the world, as he might risk arrest.

Yes, why arrest a criminal murderer instead of waiting until he feels bad enough to turn himself in?

I mean they sanctioned it. How can you sanction something without recognizing it ;)