Updated

A protester who managed to infiltrate a group of reporters shouted "treason" at President Trump and threw mini-Russian flags at him as the president arrived for a meeting Tuesday with Senate Republicans on Capitol Hill.

The startling scene played out in full view of the cameras as Trump walked down the Capitol halls with Senate Majority Leader Mitch McConnell, R-Ky.

“Trump is treason!” a man shouted from an area designated for the press.

He was identified as Americans Take Action’s Ryan Clayton. Capitol Police later announced that Clayton was arrested and charged with “unlawful conduct.”

Fox News has learned that Clayton used an outdated visitor’s pass to enter the Capitol through a tunnel connecting the Rayburn House Office building.

After clearing the security checkpoint, he made his way outside the Senate chamber, where he blended in with credentialed congressional reporters and stood just feet away from Trump.

“This was a failure on multiple levels,” said one senior source with knowledge of the security breach. “There is egg on people’s faces.”

Authorities are now reviewing security camera footage to determine the path Clayton took to surpass security and enter the second floor by the Senate chamber. There could be discipline for the officers who didn’t detect the protester, Fox News has learned.

“Some heads will roll,” added another security source.

Clayton is known for expressing his anti-Trump views by tossing Russia flags. At the Conservative Political Action Conference in February, he spearheaded the distribution of over 1,000 Russian flags with Trump's name printed across the middle.

Americans Take Action is anti-Trump, with tabs on its website dedicated to his impeachment, “Trump Puppets” and options to “Get Russian Trump Flags.”

Clayton spoke with congressional security officials after the incident.

The disruption was reminiscent of a 2008 joint-press conference with then-President George W. Bush and then-Iraqi Prime Minister Nouri al-Maliki, where an Iraqi television reporter hurled both of his shoes at Bush.

Bush dodged both shoes, and later joked at the incident, saying that all he could “report” was that the shoes were “a size 10.”

Fox News' Brooke Singman, Chad Pergram, Jason Donner and Ben Florance contributed to this report.