A federal judge refused today to free Oath Keepers founder Stewart Rhodes from jail while he awaits trial on charges that he plotted with other members of his far-right militia group to attack the U.S. Capitol to stop Congress from certifying Joe Biden’s electoral victory.

U.S. District Judge Amit Mehta said federal prosecutors have presented “compelling if not strong” evidence against Rhodes, who has been the group’s leader since its 2009 founding. Rhodes poses a “clear and convincing danger” to the public, the judge said during a remote hearing.

“His ability to communicate, organize are his greatest weapons,” Mehta said, calling Rhodes an “extremely sophisticated individual.”

Rhodes and 10 other people linked to the Oath Keepers are the first to be charged with seditious conspiracy in the Jan. 6, 2021, attack at the Capitol. Four other Oath Keepers defendants charged with seditious conspiracy remain jailed pending a trial set for July.

Their Jan. 12 indictment also charged Rhodes with obstruction of justice. Prosecutors say he tried to destroy electronic evidence of the alleged plot from his cellphone.

Rhodes, 56, has been detained in federal custody since his arrest in Little Elm, Texas, a day after his indictment. On Jan. 26, a federal magistrate judge in Plano, Texas, ordered him jailed pending trial. Rhodes’ lawyers asked Mehta to overturn that decision, but the judge rejected that request.

Prosecutors say Rhodes orchestrated the group’s assault on the Capitol with backup from an armed “quick reaction force,” or “QRF,” stationed at a Comfort Inn just across the river in Arlington, Virginia. The QRF was composed of Oath Keepers members from Arizona, Florida and North Carolina and stayed in contact with Rhodes during the attack, according to prosecutors.

“The QRF teams guarded an arsenal of firearms and related equipment and were prepared to speed those weapons into the hands of co-conspirators on the ground in Washington when directed by Rhodes or other conspiracy leaders,” prosecutors wrote in a court filing.

Rhodes’ lawyers described the QRF as a defensive force, “called if and only if required to defend members or those with whom they have been charged with protecting,” they wrote in a filing.

The indictment also alleges that two teams of Oath Keepers formed military-style “stacks” as they stormed and entered the Capitol.

During a hearing Wednesday, the judge asked a prosecutor why authorities believe the Oath Keepers didn’t activate a QRF team. Assistant U.S. Attorney Kathryn Rakoczy said they didn’t need to because group members had breached the Capitol without it.

Rakoczy referred to Rhodes as the “architect” of the plot. One of Rhodes’ lawyers, James Bright, said no such plot existed.

“There was no conspiracy to overthrow the government,” Bright told the judge. “There certainly was an enormous amount of bombastic language that was involved.”

Rhodes spent over $15,000 on firearms and related equipment in the week before the Capitol riot and bought more than $17,000 in additional firearms-related equipment between Jan. 6 and Biden’s inauguration on Jan. 20, 2021, according to prosecutors. Mehta said the quantity and timing of those gun purchases isn’t consistent with somebody buying them for self-defense.

Rhodes’ attorneys said he doesn’t pose a threat to the public or a flight risk. He voluntarily met with FBI agents multiple times after Jan. 6 and gave them his phone, they noted.

Rhodes’ lawyers say Oath Keepers believed that then-President Donald Trump would be invoking the Insurrection Act on Jan. 6, “necessitating a need for militias and other groups to defend that declaration.”

“When that did not happen, Rhodes and others took no action. They left the Capitol grounds and went to dinner,” the defense attorneys wrote.

Oath Keepers also provided security for longtime Trump backer Roger Stone and others in Washington that day, according to Rhodes’ lawyers.

The House committee investigating the Jan. 6 insurrection sought testimony from Rhodes when he appeared remotely before the panel from jail earlier this month.

Rhodes is a Yale Law School graduate and military veteran. He was living in Granbury, Texas, after the Capitol riot and has been held at a county jail in Bonham, Texas, since his arrest.

“Rhodes used his legal and military training to lead an attack on our core democratic traditions, and purposefully recruited others with similar military and law enforcement experience to join the fight,” prosecutors wrote.