WASHINGTON — A former aide to Sen. Maggie Hassan, D-NH, has reached an undisclosed plea deal with federal prosecutors on the felony charges that he posted information about Republican senators last fall during the hearings on Supreme Court Justice Brett Kavanaugh’s nomination.

Jackson Cosko, 27, was charged with publishing restricted personal information, witness tampering, threats in interstate communications, unauthorized access of a government computer, identity theft, second-degree burglary and unlawful entry.

He was asked by Hassan to resign earlier last year for “failing to follow office procedures,” according to a spokesman.

Cosko had worked in Hassan’s office from January 2017 to May 2018 as a legislative correspondent and systems administrator.

At the time of his arrest, Cosko was caught in Hassan’s Washington office using staff computers there without permission, law enforcement officials said.

When Cosko was arrested, he was an intern in the office of Rep. Sheila Jackson Lee, D-Texas. He was fired from Lee’s office after his arrest.

According to court documents in U.S. District Court in Washington, D.C., Judge Thomas F. Hogan canceled a status conference set for Thursday because the parties reached a deal behind the scenes.

Hogan set April 5 as the date to hold a hearing on the terms of that plea agreement.

Last January, Hogan approved Cosko’s release on personal recognizance bail but required he undergo high intensity supervision by the U.S. Marshals Office.

The terms of that supervision required he not possess any guns and that he submit to random drug testing if asked.

Brian W. Stolarz, one of Cosko’s lawyers, wrote in a motion earlier this month his client was “progressing significantly in his treatment.”

“The parties are in discussions to resolve the case and require additional time for that purpose,” Stolarz wrote on March 12.

The information that Cosko is charged with posting included phone numbers and home addresses for three Republican members of the Senate Judiciary Committee at the hearing: Sen. Lindsey Graham of South Carolina, Sen. Mike Lee of Utah and Sen. Orrin Hatch of Utah.

Investigators say other senators may have been targeted.

A court affidavit that described the government’s case said Cosko entered Hassan’s office late last Oct. 2, started working on computers without being allowed, and was caught by two staff members.

The federal charges of threats and witness tampering stem from an email Cosko was charged with sending to a Hassan staffer shortly after the incident.

“The email was titled, ‘I own everything,’” according to the sworn statement by a Capitol Police investigator. “The body of the email stated, ‘If you tell anyone, I will leak it all ... emails, Signal conversations, senators’ children’s health information and socials.”

Signal is a popular message application and “socials” is a reference to Social Security numbers.