Border Patrol Agent arrests illegal entry from Mexico, discovers US citizen kidnapped 35 years ago.
If someone is detained by an Agent they are asked where they were born and if they assert that they were born in the US then the Border Patrol will undertake an investigation to confirm or refute the charges. I have heard a number of cases like this one, this one made the news.
edited to add: Border Patrol agents in Imperial are raising funds to buy a plane ticket for David to see his mother.
http://www.cnn.com/2013/11/13/us/mother-son-reunited-border/index.html?iref=allsearch
(CNN) -- For a while there, Kathy Amaya thought her long-lost son was gone forever.
He was 2 years old when her estranged husband took the boy to San Luis Potosi, Mexico, to visit grandparents.
That was 35 years ago, and that was the last time Amaya, now 60, saw her son.
Then, the U.S. Border Patrol called her this month and said a man who spoke only Spanish was claiming to be a U.S. citizen -- and that she was his mother.
At long last, the day that Amaya thought would never come finally arrived.
"We didn't talk over the phone, but I heard him" in the background during the call with the Border Patrol, Amaya said. "He was right there. I was asking his birth date and what town he is from because I wanted to know if it was the same."
Through a Border Patrol agent in California, the man answered the questions correctly. He was her son. Moreover, the Border Patrol agent earlier had researched the man's birth certificate and used that document to track down Amaya in Wisconsin: "All he told me was, 'You're really hard to track down, you know that?'" she said of the agent's phone call.
Hearing her son's voice for the first time in 35 years -- though it was in the background -- was "very emotional," Amaya said.