The impeachment trial of former President Donald J. Trump largely focused on his actions leading up to the violent attack on the Capitol on Jan. 6. But there was a crucial period that day of nearly five hours — between the end of Mr. Trump’s speech at the Ellipse urging his supporters to march to the Capitol and a final tweet telling his followers to remember the day forever — that remains critical to his state of mind.

Evidence emerged during the trial about what Mr. Trump was doing during those hours, including new details about two phone calls with lawmakers that prosecutors said clearly alerted the president to the mayhem on Capitol Hill. Prosecutors said the new information was clear proof of Mr. Trump’s intent to incite the mob and of his dereliction to stop the violence, even when he knew that the life of Vice President Mike Pence was in danger.

Senator Mitch McConnell of Kentucky, the Republican leader who on Saturday voted to acquit Mr. Trump but offered a sweeping endorsement of the prosecutors’ case, backed them up: “There’s no question — none — that President Trump is practically and morally responsible for provoking the events of the day. No question about it.”

Still, many crucial questions remain unanswered about the president’s actions and mood from roughly 1 to 6 p.m. Jan. 6. Here is what is known so far:

Mr. Trump concluded his incendiary speech on the Ellipse at 1:11 p.m. He had repeatedly told the crowd that the election was stolen from him and urged his supporters to march to the Capitol in a last-ditch effort to stop President-elect Joseph R. Biden Jr.’s victory from being certified. Mr. Trump said twice that he would go with them. And days before the march, he had told advisers that he wanted to join his supporters, but aides told him that people in the crowd were armed and that the Secret Service would not be able to protect him.

Six minutes later, Mr. Trump’s motorcade began heading back to the White House. He arrived there at 1:19 p.m. as the crowd was making its way up Pennsylvania Avenue and beginning to swarm around the Capitol. Television news footage showed the mob as it moved closer to the doors.

At some point, Mr. Trump went to the Oval Office and watched news coverage of a situation that was growing increasingly tense.

At 1:34 p.m., Mayor Muriel Bowser of Washington made a formal request for assistance in a phone call with the Army secretary, Ryan D. McCarthy. At 1:49 p.m., as the Capitol Police asked Pentagon officials for help from the National Guard, Mr. Trump tweeted a video of his incendiary rally speech.

It was around this time that some of Mr. Trump’s allies publicly called on him to do something. Chris Christie, the former governor of New Jersey, told ABC News that Mr. Trump needed to say something to stop the rioting.

At 2:12 p.m., the same moment that the mob breached the building itself, Mr. Pence — who had defied the president by saying he planned to certify Mr. Biden’s victory — was rushed off the Senate floor. A minute later, the Senate session was recessed. Two minutes after that, at 2:15 p.m., groups of rioters began to chant, “Hang Mike Pence!”

Nine minutes later, at 2:24 p.m., Mr. Trump tweeted a broadside at Mr. Pence for moving ahead to certify Mr. Biden’s win: “Mike Pence didn’t have the courage to do what should have been done to protect our Country and our Constitution, giving States a chance to certify a corrected set of facts, not the fraudulent or inaccurate ones which they were asked to previously certify. USA demands the truth!”

At 2:26 p.m., after Mr. Pence had been whisked away, a call was placed from the White House to Senator Mike Lee, Republican of Utah, according to call logs that the senator provided during the impeachment proceedings.

The president had made the call, but he was actually looking for Senator Tommy Tuberville, Republican of Alabama. Mr. Lee gave the phone to Mr. Tuberville, who has told reporters that he informed Mr. Trump that Mr. Pence had just been escorted out as the mob got closer to the Senate chamber.

“I said, ‘Mr. President, they just took the vice president out, I’ve got to go,’” Mr. Tuberville recounted to Politico.

This was a significant new piece of information. House prosecutors used it to argue that Mr. Trump was clearly aware that the vice president was in danger and that he had a callous disregard for Mr. Pence’s safety. On Friday, Mr. Trump’s defense team had insisted that Mr. Trump was not aware of any peril facing Mr. Pence.

Back at the White House, advisers were trying to get Mr. Trump to do something, but he rebuffed calls to intercede, including those from people wanting to see the National Guard deployed. The president, several advisers said, was expressing pleasure that the vote to certify Mr. Biden’s win had been delayed and that people were fighting for him.

“According to public reports, he watched television happily — happily — as the chaos unfolded,” Mr. McConnell said on Saturday. “He kept pressing his scheme to overturn the election. Even after it was clear to any reasonable observer that Vice President Pence was in serious danger, even as the mob carrying Trump banners was beating cops and breaching perimeters, the president sent a further tweet attacking his own vice president.”

Senator Lindsey Graham of South Carolina, a close Republican ally of the president’s, told The Washington Post that he called Ivanka Trump, Mr. Trump’s eldest daughter, to try to get her to reason with her father. Mark Meadows, the White House chief of staff, also called Ms. Trump to see if she could talk to her father. A short time later, she arrived in the Oval Office, urging Mr. Trump to issue a statement.

The White House counsel, Pat A. Cipollone, hammered at Mr. Trump to understand that he had potential legal exposure for what was taking place.

Finally, at 2:38 p.m., Mr. Trump tweeted, “Please support our Capitol Police and Law Enforcement. They are truly on the side of our Country. Stay peaceful!”

A short time later, at 3:13 p.m., Mr. Trump added a note, “I am asking for everyone at the U.S. Capitol to remain peaceful. No violence! Remember, WE are the Party of Law & Order – respect the Law and our great men and women in Blue. Thank you!”

Ms. Trump quoted her father’s tweet when she sent out her own, telling “American Patriots” to follow the law. She quickly deleted it and replaced it when she faced blowback on Twitter for appearing to praise the rioters as “patriots.”

Around 3:30 p.m., Representative Kevin McCarthy of California, the House Republican leader and another ally of Mr. Trump’s, told CBS News’ Norah O’Donnell that he had spoken that afternoon with Mr. Trump as the Capitol was under siege.

“I told him he needed to talk to the nation,” Mr. McCarthy said. “I told him what was happening right then.”

The call became heated, according to a Republican congresswoman, Representative Jaime Herrera Beutler of Washington State, who said that Mr. McCarthy told her that Mr. Trump had sided with the mob as the Capitol attack unfolded, suggesting he had made a choice not to stop the violence.

In a statement on Friday night that was admitted into evidence in the trial on Saturday, Ms. Herrera Beutler recounted that Mr. McCarthy had a shouting match with Mr. Trump during the call.

Mr. McCarthy had told Mr. Trump that his own office windows were being broken into. “Well, Kevin, I guess these people are more upset about the election than you are,” Mr. Trump said, according to a report by CNN that the congresswoman confirmed.

“Who do you think you’re talking to?” Mr. McCarthy fired back at one point, CNN reported, including an expletive.

Meanwhile, the violence continued. At 4:17 p.m., Mr. Trump posted a video on Twitter of him speaking directly to the camera in the Rose Garden. “I know your pain,” Mr. Trump said. “I know you’re hurt. We had an election that was stolen from us, it was a landslide election, and everyone knows it, especially the other side. But you have to go home now.”

He added, “We have to have peace. We have to have law and order. We have to respect our great people in law and order. We don’t want anybody hurt.”

The violence continued. Well before the Capitol Police announced at 8 p.m. that the building had been secured, Mr. Trump put out a final tweet at 6:01 p.m.: “These are the things and events that happen when a sacred landslide election victory is so unceremoniously & viciously stripped away from great patriots who have been badly & unfairly treated for so long. Go home with love & in peace. Remember this day forever!”