Whispered, panicked calls from frightened employees barricaded in an office. Violent scenes of broken windows and pushed open doors. Frenzied audio between Capitol cops.

On the second day of the impeachment trial, the House impeachment managers showed Senators previously unseen Capitol security footage and displayed a terrifying portrait of the violence that the pro-Trump mob sparked in the Capitol on Jan. 6.

The new evidence was presented by Delegate Stacey Plaskett of the Virgin Islands, who created a methodical narrative of the day and timestamped each new video. Representative Eric Swalwell, Democrat of California, continued the presentation.

When it began, Ms. Plaskett recalled the September 11, 2001 terrorist attacks and reported that a plane was heading for the Capitol.

“Almost every day I remember 44 Americans giving their lives to stop the plane that went to this Capitol,” said Ms. Plaskett, who was serving as the adjutant at the time. “I thank them every day for saving my life and that of many other people. These Americans sacrificed their lives for the love of the country, honor, duty, and all the things America means. The Capitol stands because of such people. “

As each new video and audio clip was introduced, a map of the Capitol remained in the lower corner of the screen, with a red dot tracking the progress of the rioters in the building while more violent images flickered across the screen.

In one scene, Utah Republican Senator Mitt Romney was walking down a corridor where he met Capitol Police officer Eugene Goodman, who appeared to be warning him of the progress of the rioters. Mr. Romney ran off.

Security footage from the Capitol showed the mob pounding through windows first to break through the building before turning to other doors to break them open from the inside as rioters flooded in. Ms. Plaskett recalled the threats the rioters had made publicly against the lives of California spokeswoman Nancy Pelosi and Vice President Mike Pence.

“You were talking about the assassination of the Vice President of the United States,” said Ms. Plaskett. She added that Mr. Pence and his family never left the Capitol during the siege.

After Ms. Plaskett played scenes of lawmakers and their coworkers escaping to safety, she played audio of frightened coworkers from Ms. Pelosi’s office barricaded in a room.

“We need the Capitol Police to get into the hall,” said one, and whispered into a phone in the hope that the rioters outside would not hear anything.

Mr. Swalwell introduced perhaps the cruelest video showing the moment when Ashli ​​Babbitt, one of the rioters, was killed and warned viewers before playing the clip that it would be graphic.

As the impeachment executives played videos and never-before-heard recordings of radio communications from the Capitol Police on January 6, senators from both parties sat in tense silence. Many tried to get a better view. In the back row on the Democratic side, Senators Mark Warner from Virginia and Michael Bennet from Colorado stood up to watch.

On the Republican side, the senators showed little emotion, but paid close attention to it. Many turned their heads from the video screens just to take notes.