Kevin Alstrup of Washington DC was arrested and charged with four misdemeanour offences on 6 February, including entering and remaining in a restricted building, disorderly conduct and unlawful picketing.
Mr Alstrup was employed by the State Department as a “diplomatic security officer” at the time of the riots, according to an FBI affidavit. In that role, he would have been “familiar with providing security and protection for high-ranking government officials or sensitive locations, like embassies,” according to court documents.
Surveillance footage and still images from livestreams included in the charging documents show Mr Alstrup inside the US Capitol during the siege.
He is also pictured in livestream footage from far-right troll and convicted rioter Anthime “Baked Alaska” Gionet, who was sentenced to 60 days in prison last year after pleading guilty to riot-related charges.
Mr Alstrup’s alleged social media accounts also posted images from outside the Capitol, according to court documents. FBI agents determined that he spent roughly half an hour inside, where he appeared to be photographing rioters entering the building through broken windows. He was later captured in body-worn camera footage from law enforcement officers outside the building.
Agents used a Gmail address and Google location data associated with a device on Capitol grounds to identify him, according to the FBI affidavit.
Mr Alstrup no longer works for the State Department, though it is unclear when he stopped working with the agency. He was a “third-party contractor providing uniformed officer services for the State Department,” according to a statement from the agency.
His employer Inter-Con Security Systems Inc told NPR that the company “was just made aware of these allegations today” and “takes these matters very seriously and declines to comment on active legal matters”.
More than 1,300 people have been charged with crimes connected to the Capitol riot, when a mob of Donald Trump’s supporters breached the halls of Congress in a show of force to stop the certification of 2020 election results.
Last year, a former Trump-era State Department appointee was sentenced to nearly six years in prison for his role in the attack.
Frederico “Freddie” Klein was convicted on eight felony counts, including assault, civil disorder and obstruction of an official proceeding.
Federal prosecutors said he “waged a relentless siege on police officers” as he pushed through law enforcement outside the Capitol. Video evidence appeared to show him using a police riot shield to attack officers.
“As an employee of the federal government, Klein was endowed with the trust of the American people,” prosecutors wrote in court documents. “He violated that trust ... when he attacked the very country for which he was paid to work.”