Sen. Tammy Duckworth, an Iraqi War veteran who lost both her legs in an insurgent attack, is pressing acting Defense Secretary Christopher Miller to investigate the involvement of any current or retired military personnel in last week's riots at the Capitol.
Miller should demand each branch of the military cooperate with the FBI and Capitol Police to investigate reports that several of the pro-Trump supporters were veterans, the Illinois Democrat said in a letter to the Pentagon chief on Monday.
"If accurate, it would be a disgraceful insult to the vast majority of service members who honorably serve our nation in accordance with the core values of their respective services," Duckworth wrote.
"Upholding good order and discipline demands that the U.S. Armed Forces root out extremists that infiltrate the military and threaten our national security," she added, urging Miller to take action under the Uniform Code of Military Justice if any service members or retirees are identified.
Doing so would allow the military to prosecute retirees by recalling them to active service.
The Justice Department has already obtained indictments against several former Air Force and Army service members in the attack on the Capitol, as the FBI works to identify participants.
Meanwhile, Rep. Jason Crow, D-Colo., has requested a review of troops headed to the Capitol ahead of President-elect Joe Biden's inauguration, to ensure that members deployed to the inauguration are not "sympathetic to domestic terrorists."
Other law enforcement agencies are also under investigation and facing heavy scrutiny about their response to the violent insurgency as lawmakers gathered to certify the results of the presidential election.
Two Capitol Police officers have been suspended for their actions -- which included taking selfies with protesters and opening the gates to let mobsters into the building. Several more are under investigation.