For more than two decades, John Walsh has been hunting the country's most dangerous criminals. At the helm of the show "America's Most Wanted," Walsh has helped put more than 1,000 fugitives -- serial killers, rapists and child abductors -- behind bars.
"I have caught some of the worst of the worst," he said. "We have caught 17 guys off the FBI's 10 Most Wanted [List]."
"Nightline" accompanied Walsh behind the scenes of his show, shooting on location near San Francisco, where he's on the trail...Full Story