I'd advise you to see a private attorney or if you haven't funds for that, go to your local county courthouse and see the Family Law Facilitator who can explain how you can file a motion for custody and - this is very important- serve the father by publication. Father must be served so the order can be obtained. And right, do NOT allow your son to go to Mexico. If Father keeps him there you have some legal options to get him back but as a practical matter, not ones on which you can rely.
Answered on Jan 28th, 2016 at 9:35 AM