Federal authorities arrested a man on Monday who they say wore a Washington Capitals jersey and sprayed a fire extinguisher on the Capitol steps during the pro-Trump riot earlier this month.

Matthew Ryan Miller, 22, faces four charges after law enforcement identified him in several photos, including photos from Getty, with assistance from a witness who said they have known Miller for about seven years, according to a criminal complaint unsealed this week.

Investigators used photos and videos taken during the riot at the Capitol building to identify Miller as an individual wearing a black cowboy hat, a black backpack and a Washington Capitals red, white and blue jersey, the complaint submitted last week said.

Miller is allegedly seen in one Getty photo discharging a fire extinguisher on the Capitol steps, which authorities classified as a “dangerous weapon.” In another photo, officials say Miller is shown using a barricade to scale and assist others in climbing the Capitol walls.

Officials say that a third photo from Getty shows Miller raising a fist with the Maryland state flag and the Gadsden “Don’t Tread on Me” flag wrapped around his neck "as a cape or scarf."

The unidentified witness interviewed by authorities confirmed Miller’s identity through a photo posted to an Instagram account “recognized” as Miller’s account, the complaint states. The photo shows a man with his face covered by goggles and a black bandana with a skull tagged with the location “President’s Park (White House).”

The witness said they were “confident” the person in the picture was Miller because he “has maintained the same hairstyle for approximately seven years, and because the male suspect in the screenshot captured is consistent with Miller’s appearance and physical characteristics," the complaint reads.

Authorities said the witness believed other photos showed Miller at the riot and using a fire extinguisher “based on the similarity and likeness of physical characteristics and matching clothing from the Instagram screenshot.”

Miller is charged with entering or remaining in restricted buildings or grounds without lawful authority with a dangerous weapon and engaging in disorderly or disruptive conduct in restricted buildings or grounds with a dangerous weapon. He also faces charges of injuring an architectural feature in the Capitol grounds and violent entry and disorderly conduct on Capitol grounds. 

The 22-year-old from Howard County was ordered to be detained before his trial, with D.C. Magistrate Judge Zia M. Faruqui describing Miller’s actions as “quite severe and quite concerning” at his Monday court appearance, The Boston Sun reported.

Miller’s attorney Eduardo Balarezo reportedly told the judge there was no evidence in the complaint that asserted why Miller was at the event and that he entered the Capitol building. 

The Hill has reached out to Miller’s attorney for comment. 

A mob of Trump supporters raided the Capitol building on Jan. 6 as Congress met to certify President Biden’s electoral win. The intrusion forced both chambers to halt their Electoral College count and forced lawmakers to flee to secure locations. 

Hours later, after law enforcement secured the building, Congress confirmed Biden's Electoral College win.

The Justice Department has arrested more than 100 people allegedly involved in the riot. Five people died amid the riot, including a Capitol Police officer.