Same for terrorists. A bounty hunter who lives for the chase is willing to cross from jurisdiction to jurisdiction to track someone down. Quite routinely bounty hunters will go to Mexico to grab someone who jumped bail in California or Texas. They're more efficient than cops, who would have to notify local Mexican authorities, argue extradition, etc. Red tape dissolves when privateers are around.
Heh, that made me remember a story from an uncle that was a PI/bounty hunter and ex-security chief of a (state that borders Mexico) Governor. He entered Mexico and captured a bail jumper and had a little problem re-entering. Seems like the Mexicans aren't real happy when they find an American in the process of bringing a handcuffed Mexican back over to our side.
He was glad that he had memorized a phone number of the Governor, and after a couple of tense hours, he was allowed to cross without his prisoner. I don't think he went back to Mexico after that, at least for business purposes. Heh, learn something new and remember something old every day I guess.