Christopher Picciano, a member of Washington's elite presidential motorcade detail, was accused of saying he wanted to kill the first lady, The Washington Post reported.
Picciano's troubles began in July 2012 while having breakfast with a group of officers in a downtown restaurant. They were taking about the first lady's threat level when one of the officers said "a lot of people want to kill her."
A member of the group testified that Picciano replied "Yeah, because I want to kill her."
Picciano's attorney James W. Pressler said his client was joking.
During an investigation of the first lady threat, detectives found a derogatory job description and the depiction of the president as a communist on Picciano's LinkedIn and Facebook accounts.
Members of a departmental review board ruled Picciano should be suspended without pay for 40 days for conduct unbecoming an officer.