Many have criticised the police response, questioning how officers were so quickly overrun by rioters who stormed the US Capitol.
The United States' Capitol police did not increase staffing or prepare for the possibility that planned protests could escalate into violent riots, according to people briefed on the police response to last week's riot on Capitol Hill, the AP reported.
Many have criticised the Capitol police response, questioning how officers were so quickly overrun by rioters who stormed the building on Wednesday as Senators, Representatives, and the US vice president presided over a vote certifying electors.
The staffing was the same as a routine day, with only some officers outfitted to address a riot, it has now been revealed.
This came despite there being several warnings on social media of pro-Trump demonstrations in Washington.
A police lieutenant issued an order not to use deadly force, explaining why officers did not draw their weapons as the mob closed in on the building. Officers are sometimes ordered against escalating a situation by drawing their weapons if it is believed it could lead to a shootout.
In this instance, it left officers with little ability to resist the mob.
"They were left naked," Representative Maxine Waters, D-California. said of the police in an interview with AP. She had previously raised security concerns with the Capitol police.
"It turns out it was the worst kind of non-security anybody could ever imagine."
The Capitol Police's lacklustre response to the riots, poor planning and failure to anticipate the seriousness of the threat have drawn condemnation from lawmakers and prompted the ouster of the department's chief and the Sergeants at Arms of both the House and Senate.
As the full extent of the insurrection becomes clear, the FBI is also investigating whether some of the rioters had plans to kidnap members of Congress and hold them hostage.
Investigators are particularly focussed on why some of them were seen carrying plastic zip-tie handcuffs and had apparently accessed areas of the Capitol generally difficult for the public to locate, according to an official.
The official was among four officials briefed on Wednesday's incident who spoke to The Associated Press on the condition of anonymity because they were not authorised to discuss the ongoing investigation publicly.
Two rioters who had plastic restraints when they broke into the Capitol were arrested by the FBI on Sunday.
Much of the criticism of the response comes from the fact that this was openly planned. Trump had been urging his supporters to come to the capital and some hotels had been booked to 100% capacity - setting off alarm bells because tourism in Washington has cratered amid the pandemic.
Justice officials, FBI and other agencies began to monitor flights and social media for weeks and were expecting massive crowds.
A leader of the far-right extremist group Proud Boys was arrested coming into the city with high-powered magazine clips emblazoned with the group's logo, police said. The clips were not loaded, but he was planning to attend a rally near the White House.
But no fencing was erected outside the Capitol and no contingency plans were prepared in case the situation escalated, people briefed on the response told the AP.
Some high ranking members of the police were scattered during the riots.
The chief of police was with Vice President Mike Pence in a secure location while other officials were dispatched to handle bombs found outside the Republican and Democratic national committees.
Ashan Benedict, who leads the Washington field division for the Bureau of Alcohol, Tobacco, Firearms and Explosives, was at the bomb scene when Capitol Police captains there told him their officers were being overrun.
He immediately activated the special response team that was standing by and began to call in every ATF agent who works for him in Washington.
When they began entering the Capitol complex at 2:40 p.m., the hallways were packed with rioters.
Eventually, federal agents were able to secure the Capitol Rotunda. One officer died in the riot and at least a dozen were injured.