Despite rumblings of danger, the Capitol Police force did not request advance help to secure the legislative complex.
The bloody chaos inside the US Capitol on Wednesday came after the police force that protects the legislative complex was overrun by a mob of Trump supporters in what law enforcement officials called a catastrophic failure to prepare.
The siege of the Capitol, home to the US Senate and the House of Representatives, represents one of the gravest security lapses in recent US history, current and former law enforcement officials said, turning one of the most recognisable symbols of American power into a locus of political violence.
While events such as a presidential inauguration involve detailed security plans by numerous security agencies, far less planning went into protecting the joint session of Congress that convened on Wednesday to ratify the results of the 2020 presidential election, the officials said.
The lapse came despite glaring warning signs of potential violence by hardline supporters of President Donald Trump, who are inflamed by Trump’s baseless claims of a stolen election and hope to block the inauguration of President-elect Joe Biden.
Security initially was handled almost entirely alone by the US Capitol Police, a 2,000-member force under the control of Congress and dedicated to protecting the 51-hectare (126-acre) Capitol Grounds.
For reasons that remained unclear as of early Thursday, other arms of the US federal government’s vast security apparatus did not arrive in force for hours as rioters besieged the seat of Congress.