The U.S. Capitol Police had specific intelligence that supporters of President Donald Trump planned to mount an armed invasion of the Capitol at least two weeks before the Jan. 6 riot, according to new findings in a bipartisan Senate investigation released Tuesday, but omissions and miscommunications kept that information from reaching front-line officers targeted by the violence.

A joint report, from the Senate Rules and Administration and the Homeland Security and Governmental Affairs committees, outlines the most detailed public timeline to date of the communications and intelligence failures that led the Capitol Police and partner agencies to prepare for the “Stop the Steal” protest as though it were a routine Trump rally, instead of the organized assault that was planned in the open online.

It is the first such record of systemic deficiencies and leadership mistakes to have the endorsement of senior Democrats and Republicans — a rare bright spot in a Congress riven by partisan division as it debates how to investigate the riot’s genesis. But in a sign of the political pitfalls that remain, the report conspicuously steers clear of offering any assessments or conclusions regarding Trump’s responsibility for the mayhem, even though bipartisan majorities of the House and Senate agreed his influence was so egregious as to be impeachable.

The Senate committees’ report shows how an intelligence arm of the Capitol Police disseminated security assessments labeling the threat of violence “remote” to “improbable,” even as authorities collected evidence showing that pro-Trump activists intended to bring weapons to the demonstration and “storm the Capitol.”

“There were significant, widespread and unacceptable breakdowns in the intelligence gathering. . . . The failure to adequately assess the threat of violence on that day contributed significantly to the breach of the Capitol,” Sen. Gary Peters (D-Mich.), chairman of the homeland security panel, told reporters. “The attack was, quite frankly, planned in plain sight.”

The Post obtained hours of video footage, some exclusively, and placed it within a digital 3-D model of the building. (TWP)

The bipartisan report is the latest to examine the security failures that contributed to the violence that gripped the Capitol as Congress tallied electoral college results certifying Joe Biden’s victory in the 2020 presidential election. Its release comes just days after the Senate rejected legislation to create an independent investigative commission that passed the House with strong bipartisan support, and as lawmakers continue to wrestle with how to pay for security improvements to the Capitol campus.

Speaking on the Senate floor Tuesday, Majority Leader Charles E. Schumer (D-N.Y.) argued that the report “strengthened the argument” for appointing an independent commission, because of the “glaring” absence of any serious examination of Trump’s role.

“With the exception of a brief reference to former president Trump’s remarks at the ellipse, Senate Republicans insisted that the report exclude anything having to do with the cause of the insurrection,” Schumer said. “It is crucial — crucial — that we establish a trusted, independent record of what transpired on January 6th and what caused it.”

His counterpart came away with the opposite view.

“Our colleagues’ latest findings should guide the entire institution’s ongoing security review,” Senate Minority Leader Mitch McConnell (R-Ky.) said on the Senate floor in comments following Schumer’s. “Today’s report is one of the many reasons I am confident in the ability of existing investigations to uncover all actionable facts about the events of January 6th.”

At least seven congressional committees have launched probes into aspects of the Capitol attack, and there has been speculation that House Speaker Nancy Pelosi (D-Calif.) might seek to create a select committee to address it in lieu of an independent commission. But five months after the attack, the joint Senate investigation has made the most headway — no other panel has even come close to releasing a similar record of findings, though the Capitol Police inspector general has completed interim reports exposing a variety of deficiencies within the agency, and the Senate report includes a list of his recommendations.

The senators’ recommendations, which call for better planning, training and intelligence gathering, largely mirror those of other investigators who have examined the topic. Still, its 127 pages include new, vivid details of how poor communication and unheeded warnings left officers underequipped to face violent threats about which they had not been made aware, leaving the Capitol vulnerable to an attack that otherwise might have been preventable.

According to the report, Capitol Police intelligence officers knew as early as Dec. 21 that protesters planned to “bring guns” and other weapons to the Jan. 6 demonstration and turn them on any law enforcement officers who blocked their entry into the Capitol. They knew that would-be rioters were sharing maps of the Capitol campus online and discussing the building’s best entry points — and how to seal them off to trap lawmakers inside. But that information was shared only with command officers.

A separate security assessment dated Dec. 23 made no mention of those findings. Neither did a follow-up Dec. 30.

The only hints about what the Capitol Police’s Intelligence and Interagency Coordination Division knew appeared at the end of a 15-page report released on Jan. 3, which stated that “there is the possibility that the protesters may be inclined to become violent,” and that their desperation “may lead to a significantly dangerous situation for law enforcement and the general public alike.” But even that warning was fleeting: In the days that followed, in the Capitol Police’s daily intelligence assessments, such notes about violence were nowhere to be found.

In a statement Tuesday responding to the committees’ findings, the Capitol Police acknowledged an imperative to improve how it collects and shares intelligence internally and with its partners, saying “significant changes” have been implemented since the riot. But the agency insisted that, “At no point prior to the 6th did it receive actionable intelligence about a large-scale attack.”

“Before January 6, the Capitol Police leadership knew Congress and the Capitol grounds were to be the focus of a large demonstration attracting various groups, including some encouraging violence,” the statement read. “What the intelligence didn’t reveal . . . was the large-scale demonstration would become a large-scale attack on the Capitol Building as there was no specific, credible intelligence about such an attack.”

The Capitol Police statement adds that “neither the USCP, nor the FBI, U.S. Secret Service, Metropolitan Police or our other law enforcement partners knew thousands of rioters were planning to attack the U.S. Capitol. The known intelligence simply didn’t support that conclusion.”

The Senate committees’ report found fault with the Department of Homeland Security and the FBI for failing to provide specific warnings about the threats posed to the Capitol. According to the report’s findings, the FBI alerted the Capitol Police of potential “war” only the night before Trump’s rally, attaching the warning to a casually worded email that was shared with other law enforcement agencies — and the warning was picked up by a Capitol Police intelligence unit separate from the one that had been preparing the threat assessments.

Spokespeople for the FBI and DHS did not return requests for comment Tuesday morning.

The joint Senate investigation recommended improving the Capitol Police’s intelligence-gathering capabilities by, among other steps, housing all such specialists in one centralized unit.

But the report suggests that even with better intelligence, other governance and organizational deficiencies within the Capitol Police may have doomed its ability to respond to the riot. According to the findings, “fewer than ten” uniformed officers had actually been trained in how to use the “full suite of less-than-lethal munitions” that Capitol Police rely on for mob control, and much of the equipment in the force’s possession was either defective or inaccessible during the attack.

Senate investigators also found that leaders failed to follow arguably murky procedures for calling in reinforcements. The Capitol Police chief never filed a formal request to call in the National Guard, they determined, despite repeatedly asking his superiors to procure such backup — and the members of the Capitol Police Board still disagree about whether approving such a request needed to be a unanimous decision.

Giving the Capitol Police chief the power to call up the National Guard in emergencies is among the report’s 20 bipartisan recommendations for improving the Capitol’s security posture in the future — and the subject of forthcoming legislation from Rules and Administration Committee leaders, Sens. Amy Klobuchar (D-Minn.) and Roy Blunt (R-Mo.). The recommendations also include pointed suggestions for federal agencies, such as exhorting the Defense Department and the D.C. National Guard to devise a standing plan for protecting the Capitol and mounting a faster response to terrorist threats.

The report faults slow mobilization and poor interdepartmental communication — not any sort of stand-down order from the White House, as some Trump critics had speculated — for the fact that it took the National Guard more than three hours to respond to pleas for help from the Capitol during the attack. According to its findings, it was Army staff — not Trump — expressing early reservations about a military intervention, while the Army secretary claimed he was never informed that the D.C. National Guard had a quick reaction force “ready to go” to the Capitol, just awaiting his approval.

A spokesman for the Defense Department said Tuesday that officials are aware of the report but did not have an immediate response.

The most tangible impact of the report, which was based on public testimony, closed-door interviews from senior military personnel and additional communication with other federal officials, may come in the next several weeks, as lawmakers tackle what changes they can effect on campus.

Last month, the House narrowly passed a $1.9 billion supplemental appropriations package to pay for security improvements to the Capitol and settle accounts with the various agencies that responded to the riot. The intensely partisan reception for the measure all but guarantees that it will be narrowed as it moves through the Senate, where such legislation must procure 60 votes to avoid a procedural filibuster.

The senators who co-authored the report told reporters that they hope it provides a guide for what must be done — and that it can get the necessary bipartisan support to pass.

“It should be informing the supplemental appropriation,” said Sen. Rob Portman (R-Ohio), the top Republican on the Senate Homeland Security and Governmental Affairs Committee.