In that post, which also sought donations, Stone said Mueller's tactics were "straight out of the gestapo's playbook".
U.S. District Judge Amy Berman Jackson ordered Stone to explain at a February 21 hearing in Washington why the post didn't violate a limited gag order barring him from saying anything that might bias potential jurors in an upcoming trial.
A federal judge on Tuesday ordered Roger Stone to appear in court to consider whether to revoke his bail after the Trump confidant posted a photo on Instagram of the judge with what appeared to be crosshairs of a gun.
He later said the picture had been "misinterpreted" and that any suggestion he meant to threaten Jackson was "categorically false".
"I had no intention of disrespecting the court and humbly apologise to the court for the transgression".
The anti-secrecy group released material stolen from Democratic groups including Hillary Clinton's campaign. "This was a random photo taken from the Internet", Stone said in the statement. "Stone recognizes the impropriety and had it removed", his attorneys wrote to the court.
The photo has since been taken down from his Instagram account, but Mediaite posted a screenshot of it. District Court Judge Amy Berman Jackson's face is in the photo.
In another post, Stone wrote, "What some say are cross hairs are in fact the logo of the organization that originally posted it something called corruption central". "They use the logo in many photos". He was also charged with witness tampering and obstructing an investigation.
Stone downplayed his indictment, telling CNN's Chris Cuomo it was a "process crime" and said it does not show collusion between Wikileaks or the Russian government.