The article doesn't say when he took the kids. If he's trying to work as a doc here he will get found easily enough, you can't do that work without people knowing who you are.
I don't personally think he's in Cancun, but could be someplace near there. But to answer your question..... He took the boys on March 6, 2003 and fled with them. They were living in Houston, TX. Here is the actual FBI poster: http://www.fbi.gov/wanted/parent/nava_fo.htm It says he's also a teacher and the boys were born in Mexico. So the dude could be doing pretty much anything if he's also a Dr. Michelle
