Jackson A. Cosko illegally used a computer in the office of Democratic Sen. Maggie Hassan and and threatened a Hassan staffer later that day, court documents show. He allegedly is behind the posted personal information about Republican senators on their Wikipedia pages.

The case against Cosko is detailed in an affidavit submitted in the U.S. District Court for the District of Columbia that includes details of how Cosko allegedly posted cell phone numbers and home addresses of the senators onto the web from House and Senate computer networks.

The affidavit from United States Capitol Police Capt. Jason Bell alleges that on Oct. 2, staff from Hassan’s office called Capitol Police after they witnessed Cosko enter the senator’s office and use a computer. Cosko, a former Hassan staffer, did not have “permission or authorization” to be in Hassan’s office that night.

Cosko worked for Hassan from January 2017 until May 2018 as a legislative correspondent/systems administrator, and the court documents state that he was asked to resign.

“Senator Hassan strongly denounces the alleged actions,” said Hassan aide Aaron Jacobs. Hassan’s office is cooperating with the ongoing law enforcement investigation.

Cosko was recently an unpaid intern for Texas Democrat Sheila Jackson Lee. He no longer works there and the office is cooperating with law enforcement. 

Hassan staffers confronted Cosko and after he typed a few more things, he left the office, the affidavit shows. The witnesses from Hassan’s staff said that the computer was logged in to a staffer’s account and a program they had never used was running, according to the affidavit.

Later that night, a Hassan staffer identified as “Witness 2” in the court documents received a threatening email from livefreeorpwn@gmail.com, with the subject line “I own EVERYTHING.”

“If you tell anyone I will leak it all. Emails signal conversations gmails. Senators children’s health information and socials,” read the email.

Cosko was arrested on Wednesday and faces seven charges, including making public restricted personal information, witness tampering, unauthorized access of a government computer, identity theft, second degree burglary, unlawful entry and threats in interstate communications.

He is believed to be behind the the release of Majority Leader Mitch McConnell’s home addresses in Kentucky and Washington D.C. by adding them to public a Wikipedia page.

And during last week’s Senate Judiciary Committee hearing with Supreme Court nominee Brett Kavanaugh and Christine Blasey Ford, one of the women accusing him of sexual assault, the personal home addresses, home phone numbers, cell phone numbers and email addresses of GOP committee members Lindsey Graham, Orrin G. Hatch and Mike Lee  were added to their public Wikipedia pages from an IP address connected to the Capitol.

The Capitol Police determined that the IP addresses used to edit the Wikipedia pages during the hearing were tied to the House and the later release of McConnell’s info was done from a Senate network. Capitol Police investigators, the Senate Chief Information Officer and the House of Representatives Security Operations Center tracked down Cosko’s digital trails.

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