Roger Stone, longtime ally of U.S. President Donald Trump, arrives for a news conference in Washington, U.S., January 31, 2019.

Roger Stone, a longtime confidant and friend of President Donald Trump, apologized Monday for an Instagram post showing crosshairs near the federal judge presiding over the criminal case against him.

The Republican operative's Instagram account quickly posted and deleted the photo of District Judge Amy Berman Jackson on Monday. In an accompanying caption, Stone claimed he would only get a "show trial" from Jackson, according to photos of the post captured before its deletion. He called the her "an Obama appointed Judge who dismissed the Benghazi charges again (sic) Hillary Clinton."

Jon Swaine tweet Instagram post

In a court filing Monday night, Stone — who has pleaded not guilty to charges of witness tampering, obstruction of justice and making false statements to Congress — apologized.

"Please inform the Court that the photograph and comment today was improper and should not have been posted," a statement signed by Stone read. "I had no intention of disrespecting the court and humbly apologize to the court for this transgression."