AP IMPACT: US citizens held as illegal immigrants

For almost three months, Guzman slept in the streets, bathed in filthy rivers and ate out of trash cans while his mother scoured the city of Tijuana, its hospitals and morgues, clutching his photo in her hand. He was finally found trying to cross the border at Calexico, 100 miles away.

These days, back home in California, "He just changes from one second to another. His brain jumps back to when he was missing," said his brother, Michael Guzman. "We just talk to him and reassure him that everything is fine and nobody is going to hurt him."

In a drive to crack down on illegal immigrants, the United States has locked up or thrown out dozens, probably many more, of its own citizens over the past eight years. A monthslong AP investigation has documented 55 such cases, on the basis of interviews, lawsuits and documents obtained under the Freedom of Information Act. These citizens are detained for anything from a day to five years. Immigration lawyers say there are actually hundreds of such cases.