The Secret Service response to an armed intruder at the White House was complicated by muted alarms, thick bushes on the lawn, unlocked doors and an officer who was physically too small to tackle the intruder, a US Homeland Security Department review has revealed.
A summary of the US government's investigation into the embarrassing failure by the agency charged with protecting President Barack Obama revealed sensational new details about the September 19 break-in at the White House by a disturbed Army veteran carrying a knife.
The government determined that lack of training, poor staffing decisions and communication problems contributed to the failure that ultimately led to the resignation of the head of the Secret Service, Julia Pierson.
The new report said Omar Gonzalez climbed over a fence where an ornamental spike was missing.
An officer in the joint operations centre who tried to raise the alarm was unaware his warnings were not being broadcast to uniformed officers stationed at the executive mansion.
Some officers at a gate on Pennsylvania Avenue failed to see the fence-jumper because their view was obstructed by a construction project.
A Secret Service dog handler parked on the White House driveway was using the speaker function on his personal mobile phone without his radio ear piece and a tactical radio was stored in his locker as Gonzalez made his way into the secure area.
Two officers wrongly assumed Gonzalez would not be able to get through thick bushes on the property. Another officer posted on the portico outside the wooden White House doors mistakenly assumed the doors were locked.
Gonzalez, 42, was able to run into the building before a female officer seated just inside the building could lock a second set of doors.
That officer tried twice to take Gonzalez down but was unable because she was smaller than him.
She reached for a metal baton but mistakenly grabbed a flashlight instead. As she dropped the light and drew her gun, Gonzalez made his way into the East Room before heading back down a hallway on the State Floor deep within the White House.
Gonzalez was eventually tackled by another officer, who was helped by two plainclothes agents just finishing a shift, the report said.
Investigators said members of an emergency response team did not know the layout of the White House and hesitated to go into the mansion after the intruder.
Gonzalez has pleaded not guilty in federal court to charges of unlawfully entering a restricted building while carrying a deadly weapon, which is a federal charge, and two violations of District of Columbia law - carrying a dangerous weapon outside a home or business and unlawful possession of ammunition.