The former Democratic congressional staffer who posted personal information about Republican senators online faces nearly 50 years in prison.

Jackson Cosko, a 27-year-old Washington, D.C., resident, was arrested Wednesday by U.S. Capitol Police when he was caught sneaking into the offices of Sen. Maggie Hassan, D-N.H., after 10 p.m. Tuesday and using an aide’s computer and log-in.

He was charged with five federal offenses: making public restricted personal information, making threats in interstate commerce, unauthorized access of a government computer, identity theft, and witness tampering.

The criminal complaint against him also charges him with second-degree burglary and unlawful entry, which are both criminal offenses in D.C.

Cosko appeared Thursday afternoon before Magistrate Judge Deborah Robinson in the U.S. District Court for the District of Columbia, who ordered him detained pending a Tuesday hearing.

From August until his arrest, Cosko worked as an unpaid fellow with the office of Rep. Sheila Jackson Lee, D-Texas, which said it ended his fellowship and is cooperating in the investigation.

Prior to that, he worked for roughly 17 months as an aide to Hassan and before that was employed by former Sen. Barbara Boxer, D-Calif. According to an affidavit, five U.S. senators’ restricted personal information was posted on by Cosko.

The investigation began on Sept. 27 when it was found the Wikipedia pages of three U.S. senators had been edited to include restricted personal information without their knowledge or permission — information that included home addresses and personal telephone numbers.

Three edits took place nearly in parallel with the high-stakes Senate hearings on Supreme Court nominee Brett Kavanaugh.

Then, on Oct. 2, according to the affidavit, similar information was posted on the Wikipedia pages of two additional senators.

The senators are not named in the court documents, but the pages of Republican Sens. Lindsey Graham, R-S.C., and Mike Lee and Orrin Hatch, both of Utah, appeared to be edited during the Senate Judiciary Committee hearing on Kavanaugh.

[Click here for complete Kavanaugh coverage]

Graham, Lee, and Hatch all sit on the panel and back Kavanaugh.

The affidavit reveals that police traced the postings to IP addresses belonging to the House wired network and then determined that the computer was accessed with Cocko’s user ID and password. Other edits were done by devices using the House and Senate guest wireless networks.

According to police, Cosko tried to threaten the Hassan staffer who recognized him when he broke into the lawmaker’s office on Tuesday night.

An email message to the witness was titled “I own EVERYTHING” and said, ““If you tell anyone I will leak it all. Emails signal conversations gmails. Senators children’s health information and socials.”

The maximum prison time total for the five federal offenses is 33 years, with the Washington offenses carrying a maximum of 15 years for second-degree burglary and another six months for unlawful entry.

Cosko will be back in court Tuesday at 1:30 p.m. for a detention hearing.