The spokeswoman said Tuesday in Washington that the passenger ended his time at the department in 2006. She gave no details about his job or why he no longer works for the agency.
The man started screaming nine hours into Monday's 15-hour flight to Newark Liberty Airport. At one point, a passenger says, the man claimed people were trying to poison him. Passengers helped subdue him.
Passengers say the man was clearly not stable. The FBI says he was hospitalized after being taken off the plane.