A filmmaker who witnessed firsthand the clashes between pro-Trump rioters and police officers at the Capitol on Jan. 6 said former President Donald Trump had "enormous power" over the rioters and could have prevented the violence that day.
"I believe he had enormous power over that crowd," documentarian Nick Quested said in an interview with ABC News Chief Washington Correspondent Jonathan Karl ahead of his testimony before the House Jan. 6 select committee Thursday night.
"I think that there's a high probability that things would have been a lot calmer if he'd have asked people to stop," he said.
Quested, a veteran filmmaker who has covered conflicts around the world, has spent his career documenting other people living through dangerous and difficult situations.
A producer of visceral documentaries "Restrepo" and "Korengal," he followed U.S. service members through a deployment to a remote region of Afghanistan.
Quested has also covered the rise of ISIS in Syria and the dangerous journey of migrants through Central America.
But he said his experience following the Proud Boys and other pro-Trump rioters to the Capitol and their combat with police officers on Jan. 6 was one of the most violent situations he's ever faced.
"I'm astounded that people say it wasn't violent, because I've been in a lot of violent situations in my life, and I don't think I've seen something that's been that persistently violent for such a long period of time," he said.
War zone firefights "don't last very long," he said. "There's moments of panic and then hours of boredom."
"This is hours of panic," he said of the experience on Jan. 6.
Quested was so close to the action on Jan. 6 that he was initially considered a suspect by the FBI.
"For the first few weeks I was a subject of investigation," he said. "They couldn't figure out how I wasn't part of a conspiracy to overthrow the government."
His camera was rolling as a rioter was pushed off the balcony outside the Capitol, and as others used flag poles and makeshift weapons to attack Capitol Police officers and break into the building.
"For anyone that really didn't think that there was extreme violence in that day, I filmed it. I saw it and was subject to it. The violence was real. And it was exceptionally powerful," Quested said.
"When you see two people die on one day, you know... it's not normal political discourse," he said.
The footage, which was shared with the select committee and played during the public hearing Thursday night, showed rioters attacking Capitol Police officers with flag poles and other makeshift weapons, and pacing through the halls of Congress.
One member of Quested's team filmed rioters screaming out for House Speaker Nancy Pelosi, D-Calif., as they entered her offices, just minutes before she was evacuated from the Capitol by her security detail.
Quested, who spent weeks with members of the Proud Boys and former leader Enrique Tarrio, followed Tarrio to an underground parking garage in Washington on Jan. 5, where he met with Stuart Rhodes, the founder of the far-right Oath Keepers militia also linked to the Capitol attack.
Quested and his crew did not capture any audio of the exchange between the two far-right leaders.
"I don't know whether it's a smoking gun or not, the optics of having a meeting with Stewart Rhodes the day before the events of January 6 is terrible," he said.
Tarrio, Rhodes and members of both groups have been charged with seditious conspiracy in connection to the Jan. 6 Capitol attack.
Quested said it was "unnerving" to be in front of the camera before the committee's investigation.
"I'm usually the fly on the wall. I'm not the fly on the wall anymore," he said.
Quested said he agreed to cooperate and testify publicly because "the truth is important."
"If my testimony can help establish ... a basis of truthfulness about what really happened on that day, then I've done my job as a journalist," he said.