Frank Arthur Janssen, 63, of Wake Forest, N.C., appeared to be unharmed when the FBI's Hostage Rescue Team found him late Wednesday, an FBI spokeswoman said. He had been reported missing Saturday.
Five people have been arrested, officials said.
John Strong, special agent in charge for the FBI in North Carolina, described the kidnappers as "very dangerous people." He said the group was working on behalf of Kevin Melton, who was sentenced to life in prison in North Carolina as a habitual offender.
Melton was prosecuted by Janssen's daughter, an assistant in the Wake County District Attorney's Office.
"I'm honored and humbled to say Frank Janssen is safe and back with his family today," Strong said at a news conference Thursday. "We can only imagine the uncertainty, confusion and fear he experienced."
Janssen worked in the Washington area during the week and spent weekends with his wife in Wake Forest. His wife told police she came home Saturday to find her husband gone -- although there were signs he had returned from a bike ride -- and noticed blood drops in the yard.
While he is a government contractor with a high security clearance, officials say his daughter's job appears to have been the motive for his abduction.
[Raleigh News and Observer]