re: #3 researchok

If by treaty, even national borders.

Canada/US is an example. I don’t know if we have a similar agreement with Mexico.

Also, I do believe there has to be a good faith effort to contact the other jurisdiction.

Caveat: Please consult your interstate/international lawyer for clarification.

Here is an interesting article about international hot pursuit.

Here is another one, more specifically about the US/Mexico border.