Hardin, the former police chief in the small town of Gateway near the Arkansas-Missouri border, was serving lengthy sentences for murder and rape. He was the subject of the TV documentary "Devil in the Ozarks."

He escaped Sunday from the North Central Unit -- a medium-security prison also known as the Calico Rock prison -- by wearing an outfit designed to look like a law enforcement uniform, according to Champion. A prison officer opened a secure gate, allowing him to leave the facility. Champion said that someone should have checked Hardin's identity before he was allowed to leave the facility, describing the lack of verification as a "lapse" that is being investigated.