WASHINGTON—Tens of thousands of people from countries other than Mexico illegally crossed the Mexican border into the United States last year, creating a growing security headache for U.S. authorities.
Mexicans caught by U.S. border patrols trying to enter the country illegally are usually immediately returned to their native land.
But Mexico accepts only Mexicans, so any non-Mexicans are checked against government watch lists as a potential security or criminal threat. If their names do not appear, many are released on their own recognizance and told to appear at a deportation hearing often months in the future. The majority fail to show up for the hearing and are never seen again.