This is a red herring. It's a Federal crime to murder someone on a flight bound for or leaving the US, on a US-flagged aircraft, or for that matter to murder a US citizen anywhere in the world. It would not be handled by the local yokels, and it would most definitely be prosecuted by the Feds no matter how loudly the Mexicans squealed about their sovereignty.
-ccm
That's the problem with hypotheticals, I suppose. But in any case, the defense would be laughed out of court if it tried to argue that the U.S., Federal or State, does not have jurisdiction because the airliner is "sovereign Mexican territory." Which is the point I'm trying to make.