- It had allowed disturbed, armed Iraq veteran Omar Gonzalez to climb the White House fence and enter the building before he was apprehended near the door
- It did not realize that gunshots had hit the White House until four days after a 2011 incident
- It had allowed an armed security contractor with a record of multiple arrests to ride in an elevator with President Obama on September 16
- It had not actually apprehended Gonzalez when he entered the White House, but had in fact allowed him to run into the building's East Room before he was caught
A former agent named Joe Clancy, who retired in 2011, will act as interim director. Pierson had worked for the Secret Service for 30 years.
Correction, November 4, 2014: Due to errors in other news reports, this post stated erroneously that the contractor who rode in the elevator with President Obama was a convicted felon. The individual has been arrested multiple times but not convicted of any crime.