Two former aides to Sen. Maggie Hassan have been charged with crimes related to a hacking and doxing scheme. | Aaron P. Bernstein/Getty Images Congress Ex-Hassan aide sentenced to 4 years for doxing senators

A former aide to Sen. Maggie Hassan (D-N.H.) was sentenced to four years in prison Wednesday for hacking Senate computers and releasing personal information online about five Republican senators out of anger spurred by their roles in the confirmation hearings for Justice Brett Kavanaugh.

U.S. District Court Judge Thomas Hogan said the sentence for Jackson Cosko, 27, was needed to send a signal that criminal harassment driven by political motives would be punished severely in an era marked by extreme political polarization.


“We have…a society that has become very vicious,” Hogan said. “It’s very concerning to the court and unfortunate that you played into that.”

In April, Cosko pleaded guilty to five felonies, admitting that after being fired last year from his work as a systems administrator on Hassan’s staff, he repeatedly used a colleague’s key to enter the office, install keylogging equipment that stole work and personal email passwords, and downloaded a massive trove of data from Senate systems.

Cosko also acknowledged that after growing angry about the GOP’s handling of the Supreme Court nomination, he released home addresses and phone numbers of Sens. Lindsry Graham, Orrin Hatch, and Mike Lee on Wikipedia. After initial press coverage of that doxing, Cosko released information about Majority Leader Mitch McConnell and Sen. Rand Paul.

In a victim impact statement, Sen. Rand Paul said the event caused fear to him and his family. | Carolyn Kaster/AP Photo

Cosko said he’d received a victim impact statement only from Paul, who said the event caused fear to him and his family.

“It was a rather vicious offense,” Hogan said. “That was totally unjustified….We need to send a message out there. We need to have some deterrent and community understanding.”

Shortly before the sentence was handed down, Cosko stood at a courtroom lectern and apologized.

“I take full and complete responsibility for my actions,” he said. “I am embarrassed and ashamed for what I did.”

Cosko said that he’d been struggling with substance abuse and mental health issues and that the judge’s decision earlier this year to let him enter a treatment program was pivotal.

“I firmly believe that it saved my life,” he said.

Prosecutors had sought a 57-month sentence, while lawyers for Cosko asked for a two-year prison term.

Hogan said Cosko’s actions put senators, their families and others at risk. “You exposed them. People may want to harm them in our polarized society,” the judge said.

Prosecutor Demian Ahn said Cosko’s actions amounted to “the largest data breach in Senate history.”

“These are deliberate and malicious crimes that the defendant engaged in,” Ahn said, accusing Cosko of a “months-long, deliberately planned, meticulously executed crime spree.”

Ahn said Cosko’s offenses amounted to an attack on “civil society” and were particularly worrisome because Cosko went after most of the senators involved solely because “they had different political opinions from the defendant.”

In his two-minute statement to the court, Cosko said that he’d been struggling with substance abuse and mental health issues and that the judge’s decision earlier this year to let him enter a treatment program was pivotal.

“I firmly believe that it saved my life,” he said.

Hogan said he was puzzled at how Cosko kept up work in congressional offices given the cocaine, psychedelics and alcohol he was consuming daily.

“The probation office indicated he’s lucky he wasn’t dead,” the judge said.

Defense attorney Brian Stolarz stressed that Cosko has changed his life dramatically since his arrest last October and cooperated with investigators, leading them to hidden evidence, like computer equipment he stashed in an oven.

After the hearing, Stolarz had no criticism of the sentence, although it amounted to double what the defense had sought. “We thank the judge for this considered and thoughtful sentence,” he told reporters.

“No one should be judged by their worst act but how they emerge from it,” the defense attorney added in a statement. “Mr. Cosko is sincerely remorseful for his conduct, is in recovery, and looks forward to living a purposeful life after he serves his sentence.”

The sentencing came on the same day a second former Hassan aide, Samantha Deforest-Davis, was charged with two misdemeanors stemming from the same scheme: aiding a computer fraud and evidence tampering. She is expected to plead guilty to the two misdemeanor charges, a person familiar with the case said.

Deforest-Davis worked as a staff assistant in Hassan’s office from August 2017 until last December, when she was fired over her involvement in Cosko’s scheme, a Senate aide said.

Prosecutors say that after Cosko was fired from Hassan’s office last year, he used Deforest-Davis’s keys to repeatedly return to the office, copy dozens of gigabytes of sensitive data, and install sophisticated keyloggers that captured the work and personal computer passwords of Hassan staffers as they logged in.

Prosecutors say Deforest-Davis didn’t give Cosko permission to use her keys the first time he surreptitiously entered Hassan’s office, but the colleague later agreed to loan Cosko her office key and agreed to “wipe down” computers in the office to erase traces of Cosko’s fingerprints. Deforest-Davis and Cosko had a “close relationship” and she also owed borrowed money from Cosko to pay her rent, court papers say.

Cosko’s initial intent appears to have been to harass and intimidate his former colleagues in Hassan’s office, including those responsible for his firing, prosecutors contend. Once he had the information, he decided to use it to retaliate against GOP senators over the Kavanaugh confirmation process.

Prosecutors say Cosko also threatened to release health information on senator’s children and appeared to engage in an extortion effort by declaring in one post on Paul’s Wikipedia page: “Send us bitcoins.”

A spokesman for Hassan, Aaron Jacobs, praised law enforcement for investigating and prosecuting Cosko.

“Senator Hassan is very grateful to Capitol Police and the U.S. Attorney’s Office for their work to bring this individual to justice for the crimes he committed.”

Asked about the new charges against Deforest-Davis, Jacobs said Hassan “appreciates the work of Capitol Police and the U.S. Attorney’s Office in pursuing justice in this case.”

No arraignment has been set yet for Deforest-Davis. House salary records show she worked briefly earlier this year as a legislative correspondent for Rep. Abigail Spanberger (D-Va.).

A spokesperson for Spanberger didn’t immediately respond to requests for comment for this story.

CORRECTION: An earlier version of this story misstated when Davis began work in Hassan’s office. She started there in August 2017.