Jackson Cosko, who calls himself a “Democratic Political Professional” with cybersecurity expertise, is accused of multiple crimes for allegedly doxxing Republican Senators during the Brett Kavanaugh/Christine Blasey Ford hearings.

Jackson Cosko has now been sentenced to four years in prison for his role in the matter.

The United States Capitol Police arrested Cosko, saying he allegedly “posted private, identifying information (doxing) about one or more United States Senators to the internet,” a statement said. On October 9, 2018, a judge said Cosko should continue to be held without bond.

According to Legistorm, he worked for U.S. Sen. Maggie Hassan (D-NH) and previously worked for Sen. Barbara Boxer (D-CA). He previously worked or was an intern with the office of Sen. Dianne Feinstein, D-CA, according to Fox News. A September 2018 letter from Sheila Jackson Lee (D -TX) identified him as a staffer for her office at that time. Rep. Sheila Jackson Lee is a member of the U.S. House Judiciary Committee. (A different person working for Hassan was the intern suspended for shouting F*** you at President Donald Trump recently.)

Jackson Lee’s office identified Cosko as an intern and said he was fired because of the accusations.

According to online records, Cosko is being held at the D.C. Department of Corrections’ Central Detention Facility.

Jackson Cosko is the son of Democratic donors from California; his father donated $2,500 to Dianne Feinstein and his mother donated $500 to Hillary Clinton, according to federal records. You can see screenshots of the donations later in this article. Jackson Cosko has given small amounts over the years himself through ActBlue to Democrats like Bernie Sanders and Claire McCaskill.

Here’s what you need to know:

1. Jackson Cosko Was Accused of Everything From Witness Tampering to Identity Theft

The doxxing suspect was identified as Jackson A. Cosko, age 27, of Washington D.C. He was initially charged with making public restricted personal information; witness tampering; threats in interstate communications; unauthorized access of a government computer; identity theft; second-degree burglary and unlawful entry. You can read the Capitol police press release here.

The statement said the “investigation will continue and additional charges may be forthcoming.”

NEW: Capitol Police have arrested a suspect who they beleived doxed GOP Senators During the Kavanaugh/Dr Ford hearing last Thursday: pic.twitter.com/XOrociUoex — Frank Thorp V (@frankthorp) October 3, 2018

You can read the criminal complaint filed against Cosko in D.C. federal court below or here:

According to Roll Call, on Monday, October 1, 2018, “Majority Leader Mitch McConnell’s home addresses in Kentucky and Washington D.C. were added to his public Wikipedia page.” The site added that, during the Senate Judiciary Committee hearing involving Brett Kavanaugh and his accuser Christine Blasey Ford, “the personal home addresses, home phone numbers, cellphone numbers and email addresses of Sens. Lindsey Graham, R-S.C., Orrin G. Hatch and Mike Lee, both R-Utah, were added to the public Wikipedia pages from what appeared to be an IP address connected to the Capitol.” The information was then sent to thousands of people through an automated Twitter account that tracks Wikipedia account changes from Congress.

According to the complaint (which doesn’t name the various affected politicians), on September 27, 2018, the staff of “U.S. Senator 1” notified the Threat Assessment Section of the Capitol Police to report that an unknown person had edited the Wikipedia page for that senator, adding the senator’s restricted personal information, such as private home addresses, personal cell phone numbers, and office numbers.

The investigators tracked the IP address that was used to edit the page. The staff of a Senator referred to as Senator 6 then reported the publication of the first senator’s information to Wikipedia as well as that of two other U.S. Senators.

The Wikipedia edits revealing the senators’ personal information “occurred roughly contemporaneously with public and highly publicized Senate proceedings related to a nomination for the U.S. Supreme Court,” the complaint says, adding that the IP addresses both belonged to the House of Representatives in Washington D.C.

It was determined that one of the IP addresses was assigned to the open Wi-Fi network assigned to the House of Representatives and the person posting it was using a portable computer device. The investigators learned that Twitter posts showed the restricted personal information that had been published on Wikipedia. Other Senators were also affected.

The complaint says that the Wikipedia page for U.S. Senator 4 was also edited to add statements such as, “He dares call for an investigation of ME?!?!?!?!” and “I am the Golden God!” and “Also It’s my legal right as an American to post this info” and “We are malicious and hostile.” Other statements said “send us bitcoins” and “Wednesday night will be doxxed next.”

The investigators then used “House cybersecurity tools” and allege they identified the user as Jackson Alexander Cosko, described as a “current fellow working in the Washington D.C. office of U.S. Representative A, of the House of Representatives.” Because the computers in the House are password protected, the user was someone who “possessed Cosko’s user identification and password.”

A witness reported seeing Cosko in a Senator’s office using a computer without permission, according to the complaint. Cosko was a former staff member with the senator’s office and had been asked to resign several months before.

The complaint also alleges that a witness received a threatening email that read, “I own EVERYTHING.” It said, “If you tell anyone I will leak it all. Emails signal conversations gmails. Senators children’s health information and socials.”

Investigators believe socials was a reference to social security numbers.

According to Fox News, Cosko “was discovered by aides Tuesday night working on a computer in a Capitol Hill office that did not belong to Jackson Lee,” and added that, although the home addresses published were real, the phone numbers were not all correct, with one for Lindsey Graham actually going to the “Sexual Minority Youth Assistance League.”

Maxine Waters released a statement demanding retraction from sites that had falsely blamed a staffer of hers.

Please read my statement regarding the Capitol Police arrest of a suspect charged with doxing U.S. Senators: pic.twitter.com/9tGRgCaaWb — Maxine Waters (@RepMaxineWaters) October 5, 2018

A post in 2016 indicated Cosko used to work as a staffer for Democratic Senator Barbara Boxer. “Padres in our nation’s capital for Close Up: Washington D.C. Thanks to Jackson Cosko ’09, a staffer for Senator Boxer, for meeting with us!” read the tweet from Serra High School.

2. Jackson Cosko Says He Worked for the United States Senate Through May 2018 & a Letter Indicates He Was on Jackson Lee’s Staff in September 2018

On his LinkedIn page, Cosko brands himself as a “Democratic Political Professional & Cybersecurity Graduate Student” who lives in the Washington D.C. Metro Area.

As his top work entry, he lists “United States Senate,” and states that he was a legislative correspondent and systems administrator from January 2017 through May 2018 in the Washington D.C. area. However, the Jackson Lee letter indicates he was working in her office as late as September 2018. Politico reported that Cosko left Hassan’s office in May, so he appears to not have updated his LinkedIn page after that.

The letter starts, “I invite you to join me as an original co-sponsor of the Protect Lives and Stop the Imminent Chaos (PLASTIC) Act. The PLASTIC Act would establish a prohibition on the use of 3D printing technology to produce firearms, firearm components, or ammunition. It would also prohibit their possession and transfer.” At the bottom, it says, “Please join me as an original co-sponsor of the PLASTIC Act. To co-sponsor this legislation please contact Jackson Cosko on my staff at Jackson.Cosko@mail.house.gov” and then lists a phone number.

Here is the part of the letter mentioning Jackson Cosko. It’s dated September 10, 2018.

On LinkedIn, for the earlier position, he described his duties as the following: “Assist senior staff with issues before the Commerce Committee including technology, telecommunications, transportation; as well as with cybersecurity matters before the Homeland Security Committee.”

Fox has learned that Jackson Cosko, charged by USCP w/allegedly doxing senator(s), had worked w/Dem TX Rep Sheila Jackson Lee, fmr Dem CA Sen Barbara Boxer & current Dem NH Sen Maggie Hassan. — Chad Pergram (@ChadPergram) October 3, 2018

He listed three other positions with the Senate. He said that he worked for seven months as a press assistant and systems administrator for the Senate from July 2016-January 2017. “Also served as a Legislative Research Assistant covering technology, cybersecurity, space, science, and telecommunications,” he wrote.

He also wrote that he served as a staff assistant from April through July 2016 and as a press intern from January 2016 through March 2016. His Twitter page is deleted.

3. Jackson Cosko Worked as a Field Organizer for a PAC, Donated to Bernie Sanders & His Parents Have Donated to Top Democrats

Jackson Cosko is the son of Deborah and Greg Cosko, of California, online records show. Deborah Cosko has a photo on her Facebook page of her with her son in front of the White House. She also has a Facebook page photo showing her with Nancy Pelosi, although it’s not clear where it was taken or in what context. She posted the picture in January.

Federal records show Deborah Cosko donated $250 to Hillary Clinton both in 2015 and 2008. Jackson’s father, Greg Cosko, donated $2,500 to Feinstein in 2012.

Greg Cosko is listed as president and CEO of a company called Hathaway Dinwiddie. That company has been involved in the building of some major projects.

On LinkedIn, Jackson Cosko also indicated that he worked as a server for a restaurant from December 2015 through 2016.

In addition, from July 2015 through November 2015, he wrote that he was a “lead field organizer” for Generation Forward Pac in Des Moines, Iowa.

He wrote that he worked as a volunteer for Change Inc. as a “community development specialist/case manager” in Washington D.C. on “poverty alleviation” in 2012-2014. He solicited donations and advocated for clients with governmental agencies.

On Facebook, Cosko followed the pages of many top Democrats, including:

He also worked as a youth sports program assistant for the Peninsula YMCA and was a 2008 recipient of the YMCA national organization “Star Volunteer” award. A series of small campaign donations come up for him on the federal website through ActBlue. For example, one $25 donation was earmarked for Doug Jones for Senate and $5 and $15 earmarked for Claire McCaskill, a Democrat from Missouri.

He also donated to Bernie Sanders more than once in small amounts. Here is one such donation:

On his Pinterest page, he wrote, “Knowin nothin in life but to be legit.”

4. Cosko Was an Intern for the U.S. House of Representatives

In addition to his work with the U.S. Senate, Cosko was previously an intern with the U.S. House of Representatives. He said he held that position for six months, from August 2012 through January 2013.

He listed his duties as: “Assisted in planning and execution of fundraising, campaign, and other special events. Conducted research on impact issues and drafted press releases, letters to level government officials and agencies, as well as conducted social media campaigns in order to capitalize on earned media. Maintained databases of important media, donor, and constituent contacts for media/campaign efforts.”

In 2011, he was also an intern for the U.S. Senate. He listed his job duties as: “Attended Congressional hearings and briefings, conducted background research on salient political issues, and provided concise analyses and policy recommendations. Responded to constituent phone calls, letters, and requests. Provided constituents with case work assistance, advocating with Federal, state, and local government agencies. Supported executive assistant and scheduler with curating daily schedule of the Senator.”

His page does not list the names of politicians he worked for, however.

5. Cosko Studied Engineering & Cybersecurity

Cosko wrote on LinkedIn that he was receiving a master’s of engineering degree from George Washington University in the field of cybersecurity policy and compliance.

He indicated that his expected graduation date was 2020. He has a bachelor’s degree in political science and communications, earning it in 2014.

On Facebook, where he doesn’t have much publicly visible, Cosko wrote that he lives in Washington, District of Columbia and is from Burlingame, California.

Brett Kavanaugh, his wife, and his accuser Christine Blasey Ford have all reported receiving death threats as security and tensions remain high during the contentious Supreme Court nomination process.

This post has been updated with the campaign donations of Cosko and his parents.