Thread by @Reuters

The chaos inside the U.S. Capitol 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 reut.rs/35fSFoq

The siege of the Capitol represents one of the gravest security lapses in recent history, current and former law enforcement officials said, turning one of the most recognizable 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 to ratify the results of the 2020 presidential election, officials said

That lapse came despite glaring warning signs of potential violence by hardline supporters of Trump, who are inflamed by his baseless claims of a stolen election and hope to block the inauguration of President-elect Joe Biden

And security initially was handled almost entirely alone by the U.S. Capitol Police, a 2,000-member force under the control of Congress and dedicated to protecting the 126-acre Capitol Grounds

For reasons that remained unclear, other arms of the U.S. federal government’s vast security apparatus did not arrive in force for hours as rioters besieged the seat of Congress

The Capitol is a short walk from where Trump in a speech railed against the election just before the riot began, calling the vote an 'egregious assault on our democracy' and urging his supporters to 'walk down to the Capitol' in a 'Save America March'

Despite weeks of threats on social media that planned pro-Trump protests could descend into violence, the Capitol Police force did not request advance help to secure the building from other federal agencies such as the Department of Homeland Security, a senior official said

National Guard reinforcements, summoned by the city’s mayor, were not mobilized until more than an hour after protesters had first breached the barricades

In stark contrast, those agencies were aggressively deployed by the Trump administration during last summer’s police brutality protests in Washington and elsewhere in the United States

Read more on how security failures enabled a mob of Trump supporters to storm the U.S. Capitol reut.rs/35fSFoq by @JTanfani @johnshiffman @bradheath and Mark Hosenball