Capitol Police Inspector General Michael A. Bolton has investigated the force's missteps since the siege, when hundreds of President Donald Trump's supporters broke into the building and sent lawmakers fleeing for their lives. In a report obtained by The Associated Press, he paints a dire picture of his agency's ability to respond to future threats and casts serious doubt on whether the force would be able to respond to another large-scale attack.

The Capitol Police have so far refused to publicly release the report — prepared in March and marked as “law enforcement sensitive” — despite congressional pressure. Democratic Re. Zoe Lofgren of California, who heads the House Administration Committee, said last month that she found the report, along with another the department had circulated internally, “detailed and disturbing.” Lofgren's committee is holding Thursday''s hearing.

Bolton found that the department''s deficiencies were — and remain — widespread: Equipment was old and stored badly; officers didn't complete required training; and there was a lack of direction at the Civil Disturbance Unit, which exists to ensure that legislative functions of Congress are not disrupted by civil unrest or protest activity.

That was exactly what happened on Jan 6 when Trump supporters violently pushed past police and broke into the Capitol as Congress counted the Electoral College votes that certified Joe Biden's victory.

The report also focuses on several pieces of missed intelligence, including an FBI memo sent the day before the insurrection that then-Capitol Police Chief Steven Sund told lawmakers he never saw. The memo warned of threatening online postings by Trump backers, including one comment that Congress “needs to hear glass breaking, doors being kicked in” and blood being spilled.

“Get violent ... Stop calling this a march, or rally, or a protest," read one post recounted in the memo. "Go there ready for war. We get our President or we die. NOTHING else will achieve this goal.”A separate report prepared by the Department of Homeland Security in December alerted the police to messages on a blog where people appeared to be planning for Jan. 6. One online post included a map of tunnels under the Capitol used by lawmakers and staff. “Take note,” the message said.

The Capitol Police said in a statement Wednesday that officials had already made some of the improvements recommended in the report, and that the siege was “a pivotal moment” in history that showed the need for “major changes” in how the department operates. Still, they said that they would need more money and staff to make improvements.

“It is important to note that nearly all of the recommendations require significant resources the department does not have,” the statement said.