In order to enter another country, he will need a visa to enter. He is an internationally famous pervert. They won't give him one.
He's gonna need some big bucks for bribes and fake documentation to get out of this country and into another one.
Actually, not all countries require visas to enter as a tourist. For example, Karr could enter certain Asian nations with just his passport. Now, to work there legally, of course, he would need to apply for a work visa, but many travellers work in English language schools without one, so, who knows? Perhaps, this guy will be back trolling the streets of, say, Manila, Jakarta, Saigon, etc.
Let us just hope that his notoriety will follow him everywhere and keep him out of this profession and far away from children. Perhaps he'll just join NAMBLA and move to the Bay Area and get his gender-reassignment surgery paid for by some charity organisation up there. Twisted...absolutely twisted!
P.S. I don't know if a registered sex offender can leave the United States or not without permission, so I can't say anything definitive about how Karr's whereabouts will be tracked.