New footage from inside the hotel hosting the White House Correspondents' dinner shows the crucial moments the alleged gunman sprinted past guards after hiding a shotgun beneath his long coat.
Amid confusion over whether Cole Tomas Allen ever actually fired his weapon before Secret Service members detained him, Jeanine Pirro - Washington DC's top prosecutor - shared a high-quality clip of the incident to social media.
The footage Pirro shared appears to show Allen, a 31-year-old from California, wearing a long dark coat as he walked through the Washington Hilton hotel just minutes before the shooting on April 25.
He was seen slipping into a side room, as around a dozen members of the Secret Service and security teams stand around in the corridor.
Some were seen dismantling a metal detector at the venue.
A security guard and a K9 unit were seen momentarily investigating Allen, but both left after just a few seconds.
It was then that Allen burst out of the room without his long coat while holding the weapon, which prosecutors said was a 12-gauge shotgun.
He sprinted past several guards, with many pulling their own weapons in response.
The DoJ suggested that the footage showed Allen fired at a Secret Service member, highlighting an apparent flash from the muzzle of his gun, though the Daily Mail is currently unable to verify this.
The footage also seemed to show Allen skulking around the hotel the night before the dinner, in an apparent effort to case the place.
He was seen walking around the hotel's corridors, before walking into the gym and having a look around.
Pirro wrote in the social media post in which she shared the footage: 'We are releasing video already provided to US District Court showing Cole Allen shoot a US Secret Service officer during his attempt to assassinate the President at the White House Correspondents' Dinner.
'There is no evidence the shooting was the result of friendly fire. The video also shows Allen casing the area in the Hilton Hotel the day before the attack.
'My office along with the FBI will continue this extensive investigation to bring Cole Allen to justice.'
However, in a memo filed to court on Wednesday, prosecutors referred to an officer firing five times, but do not mention the officer being shot.
Earlier, US Secret Service director Sean Curran said Allen was not stopped by his organisation, but was instead taken down after he tripped on a box used to transport a metal detector.
Curran claimed that Allen was not hit by any of the five shots he said were discharged by a Secret Service agent.
Allen was charged on Monday with attempting to assassinate the US president.
The incident took place on Saturday April 25 and resulted in Allen's arrest at the hotel.
He said in an interview with Fox News: 'All the evidence that I've seen, the suspect shot our officer point-blank range with a shotgun.'
'Our officer heroically returned fire while being shot point-blank range in the chest with a shotgun, he was able to get off five shots.'
'It appears that the suspect hit his knee while being engaged by the officer on one of our magnetometer boxes and began to fall to the ground.'
'That's what appears to be, and at that moment is when officers and agents were able to subdue him and pile on top of him.'
The Washington Post reported, however, that just four shots were fired - all of them by the Secret Service agent.
Allen was charged on Monday with attempting to assassinate the US president, transportation of firearms to commit a felony and unlawful discharge of a firearm during violence.
He has not yet entered a plea in the case, though yesterday agreed to remain in federal custody as his case progresses.
Trump and other top US officials were quickly rushed out of the Washington Hilton hotel as shots rang out.
This courtroom sketch depicts Cole Tomas Allen, seated centre, the California man arrested in the shooting incident at the correspondents dinner in Washington.
Trump, when asked if he would wear a bulletproof vest, did not appear to be keen.
'I don't know if I can handle looking 20 pounds heavier,' he said. 'I guess it's something you consider. In one way you don't like to do it because you're giving in to a bad element.'
The incident has revived concerns about the safety of the US president and other top officials amid a pattern of political violence in the United States.