A former police officer will stand trial for his alleged role in the January 6 attack on the US Capitol

• A former police officer is facing the third trial stemming from the January 6 attack on the Capitol.
• Prosecutors accused Thomas Robertson of buying firearms after his indictment on January 6 charges.

Months after his indictment on charges stemming from the Capitol attack, Thomas Robertson wrote in an online gun forum that the Justice Department had taught accused rioters a lesson — but "definitely not the intended lesson."

"I have learned very well that if you dip your toe into the Rubicon ... cross it," Robertson wrote on the website Gunbroker.com, according to a court filing. "Cross it hard and violent and play for all the marbles."

Robertson is putting that lesson to the test Monday, when he is set to become the third accused Capitol rioter to stand trial on charges from the January 6 insurrection.

A former police officer in Rocky Mount, Virginia, Robertson was off-duty when he stormed the Capitol alongside a fellow officer, Jacob Fracker, on January 6, prosecutors said. Once inside, the two posed in front of a statue of John Stark — a general in the Continental Army during the American Revolution — with Fracker flashing his middle finger, according to a court filing.

Both were later fired by the Rocky Mount Police Department.

For federal prosecutors, Robertson's trial comes on the heels of consecutive courtroom victories. In March, a jury took just hours to return guilty verdicts in the first trial connected to the January 6 attack on the Capitol.

Later in March, a federal judge found another accused rioter guilty of trespassing on restricted Capitol grounds—a misdemeanor with a maximum sentence of a year in prison — but acquitted him of a separate disorderly conduct charge.

Those convictions have coincided with mounting pressure on Attorney General Merrick Garland and the Justice Department to hold former President Donald Trump accountable for his efforts to overturn the 2020 election.

In recent weeks, the New York Times and Washington Post have reported that the Justice Department's investigation has widened to include figures involved in the planning of a pro-Trump rally that preceded the Capitol attack on January 6 and the push by some of the former president's allies to promote slates of fake electors.

Robertson's trial is expected to feature testimony from Fracker, who pleaded guilty in March to conspiring to obstruct the joint session of Congress on January 6.

As part of his plea deal, Fracker agreed to cooperate with the Justice Department and testify that he and Robertson conspired to bring tactical gear, including gas masks, to the Capitol on January 6 to disrupt the certification of Joe Biden's electoral victory. Fracker faces a maximum sentence of 5 years in prison.

After their arrest in January 2021, authorities released Robertson and Fracker. But a federal judge ordered Robertson back to jail in July after the Justice Department presented evidence that he purchased more than 30 firearms while under federal indictment. A search of his home had turned up an M4 rifle, a partial pipe bomb, and two fuses used on training grenades.

In court papers seeking his pre-trial detention, prosecutors emphasized Robertson's past employment as a police officer and social media posts after January 6 that showed a "sincere commitment to violence."

Robertson, "holding a position of public trust as a police officer, traveled to the District of Columbia and participated in one of the most riotous acts of insurrection the nation has ever seen," prosecutors wrote. "Then, he repeatedly and flagrantly disregarded the Court's orders not to possess firearms despite being admonished for violating this condition of his release shortly after his initial arrest.

In ordering him back to jail, Judge Christopher Cooper said Robertson likely committed a new felony offense by having the firearms shipped on his behalf.

Cooper, an Obama appointee to the federal trial court in Washington, DC, said Robertson appeared to have also attempted to conceal the purchase by attaching the label "Wedding Photos" to a $3,700 transaction over financial transaction platform Venmo for the firearms.

"The undisputed facts demonstrate a concrete risk that Robertson might participate in or provide material support to acts of ideologically motivated violence if released at this time," Cooper wrote. "His recent social media posts may contain elements of bravado and hyperbole, but they provide evidence that Robertson is sympathetic to calls for a violent 'revolution,' and has been further radicalized by his pending prosecution."

Cooper is set to preside over jury selection Monday. If convicted, Robertson faces a potential years-long sentence in federal prison.