WASHINGTON >> President Barack Obama rode an elevator this month with an armed security contractor who had three criminal convictions, a violation of Secret Service security protocols, according to published reports.

The latest embarrassment for the Secret Service comes after agency Director Julia Pierson on Tuesday took full responsibility for a Sept. 19 breach of security when a man carrying a knife got into the White House. The Washington Examiner and The Washington Post reported that the elevator incident took place during Obama’s Sept. 16 visit to the Centers for Disease Control and Prevention in Atlanta.

The Post said agents questioned the contractor and discovered his criminal history after he refused to stop video recording the president with a phone camera.

Agents didn’t know he was armed until a supervisor fired the contractor on the spot and the man turned over his gun, the newspapers said.

A Secret Service spokesman confirmed the incident but declined to comment further, citing an ongoing investigation of the event.