Impeachment article has 200 cosponsors: US rep.

Rep. Markwayne Mullin, R-Okla., said he witnessed the moment a police officer fatally shot a woman inside the U.S. Capitol on Wednesday, as Trump supporters stormed the building.

Mullin said the shooting happened as an angry, pro-Trump mob that had been protesting outside broke into the Capitol building and attempted to force entry into the House chamber, which was still in session.

"They were trying to come through the front door, which is where I was at in the chamber, and in the back they were trying to come through the speaker's lobby, and that's problematic when you're trying to defend two fronts," Mullin told ABC News Chief Anchor George Stephanopoulos in an interview Thursday on "Good Morning America."

"When they broke the glass in the back, the (police) lieutenant that was there, him and I already had multiple conversations prior to this, and he didn't have a choice at that time," Mullin said. "The mob was going to come through the door, there was a lot of members and staff that were in danger at the time. And when he [drew] his weapon, that's a decision that's very hard for anyone to make and, once you draw your weapon like that, you have to defend yourself with deadly force."

A U.S. Capitol Police officer in plainclothes fired his service weapon as "multiple individuals" tried to gain access to the House room, striking a woman. She was transported to a local hospital where she was pronounced dead, according to Robert Contee, chief of the Metropolitan Police Department of the District of Columbia. Authorities have not yet released the woman's identity.

Mullin said police "showed a lot of restraint" and "did the best they could."

"That young lady's family's lives changed and his (the officer's) life also changed," Mullin said. "But what also happened is that mob that was trying to go through that door, they left. And his actions will may be judged in a lot of different ways moving forward, but his actions I believe saved people's lives even more. Unfortunately, it did take one though."

Mullin said he "never thought" he would witness such a scene unfold in the United States.

"I get people being passionate and being frustrated, but there's a right way and and wrong way to do things and yesterday was wrong. There was absolutely no excuse for it," he said. "We're very fortunate a lot more people didn't actually lost their life. One is way too many."

A West Virginia lawmaker was among the people -- mostly pro-Trump protesters -- who broke into the U.S. Capitol on Wednesday. 

Del. Derrick Evans took a video of himself and others rushing into the building after attacking Capitol police. In it, he is seen wearing a helmet and yelling, "We're in! Keep it moving, baby!"

Once inside, Evans walked around the Capitol Rotunda, which is filled with historical works of art, and yelled, "No vandalizing!"

He has since deleted the video from his social media. 

According to The Associated Press, State House of Delegates Speaker Roger Hanshaw said Evans will need to "answer to his constituents and colleagues regarding his involvement in what has occurred today."

"I want to thank everyone for their prayers today," Evans wrote in a Facebook statement after the Capitol break-in. "I am on the bus headed back home to WV. As many of you know, for the last few years I have traveled across the country to film many different events. Today, I had the opportunity to film another event in DC. I want to assure you all that I did not have any negative interactions with law enforcement, nor did I participate in any destruction that may have occurred. I was simply there as an independent member of the media to film history."

Biden officially announced key nominations for the U.S. Department of Justice on Thursday.

Judge Merrick Garland is his nominee for attorney general, Lisa Monaco is his nominee for deputy attorney general, Vanita Gupta is his nominee for associate attorney general, and Kristen Clarke is his nominee for assistant attorney general for the department's civil rights division.

Biden said he is "honored" that the nominees have "accepted this call to serve at such a critical time in our nation’s history."

"Our first-rate nominees to lead the Justice Department are eminently qualified, embody character and judgment that is beyond reproach, and have devoted their careers to serving the American people with honor and integrity," Biden said in a statement Thursday. "They will restore the independence of the Department so it serves the interests of the people not a presidency, rebuild public trust in the rule of law, and work tirelessly to ensure a more fair and equitable justice system. They are among the most accomplished legal minds in our country who also reflect the best of America’s full range of talents and background."

Hours after a pro-Trump mob broke into the U.S. Capitol to protest the results of the 2020 election, congressional tellers have ascertained Joe Biden and Kamala Harris have won.

The announcement was made by Minnesota Sen. Amy Klobuchar at 3:39 a.m. Thursday.

Vice President Mike Pence then repeated the totals at 3:40 a.m., first for president, then for vice president.

Biden will take Trump's place in the White House on Jan. 20.

Rep. Louie Gohmert and other House Republicans attempted to object to Wisconsin but did not have a senator join the objection. Gohmert said a senator withdrew his objection.

Biden and Harris finished with 306 electoral votes, while Trump and Pence finished with 232.

In a statement tweeted by White House Deputy Chief of Staff Dan Scavino following the news, Trump said: "Even though I totally disagree with the outcome of the election, and the facts bear me out, nevertheless there will be an orderly transition on January 20th. I have always said we would continue our fight to ensure that only legal votes were counted. While this represents the end of the greatest first term in presidential history, it's only the beginning of our fight to Make America Great Again!"

This is the first time Trump has publicly accepted Biden's victory and agreed to a peaceful transfer of power.

-ABC News' John Parkinson