The US Capitol Police are reporting that Capitol Police Officer Brian D. Sicknick died on Thursday night (US time) because of injuries sustained while on duty during Wednesday's riots at the Capitol.
The report said Sicknick was responding to the riots at the Capitol and was injured while physically engaging with protesters.
He returned to his division office and collapsed.
Sicknick was taken to a local hospital where he succumbed to his injuries.
His death would be investigated by the Metropolitan Police Department's Homicide Branch, the Capitol Police and federal investigators.
Democratic leaders of the House Appropriations Committee said the "tragic loss" of a Capitol police officer "should remind all of us of the bravery of the law enforcement officers who protected us, our colleagues, Congressional staff, the press corps and other essential workers″ during the hourslong takeover of the Capitol by pro-Trump protesters.
President Donald Trump today finally conceded his election loss to President-elect Joe Biden, saying now Congress had certified the results, the "new administration will be inaugurated on January 20" and his "focus now turns to ensuring a smooth orderly and seamless transition of power".
The president also condemned the violence of his supporters who stormed the nation's Capitol, saying they "do not represent our country" and they "defiled the seat of American democracy".
He labelled the siege on the Capitol Building a "heinous attack" that left him "outraged by the violence, lawlessness and mayhem".
Trump did not address his role in inciting the riots, but he did tell his supporters that, while he knows they are "disappointed," he wants them to know "our incredible journey is only just beginning".
- AP
Ryan Bridge breaks down how the Electoral College works. Video / Ben Dickens