According to a U.S. Capitol Police announcement, they have arrested a man named Jackson A Cosko, 27, for publishing the private information of at least one senator online:

WASHINGTON DC – Today, the United States Capitol Police arrested the Suspect who allegedly posted private, identifying information (doxing) about one or more United States Senators to the internet. Jackson A. COSKO, age 27, of Washington, D.C., has initially been charged with 18 USC § 119 Making Public Restricted Personal Information; 18 USC § 1512(b)(3) (Witness Tampering); 18 USC § 875(d) (Threats in Interstate Communications); 18 USC §1030(a)(3) (Unauthorized Access of a Government Computer); 18 USC § 1028(a)(7) (Identity Theft); DC Code § 22-801(b) (Second Degree Burglary), and DC Code §22-3302 (b) (Unlawful Entry).

The investigation will continue and additional charges may be forthcoming. (link)

Jackson Cosko is a staff member for Democrat Representative Sheila Jackson Lee and a former staff member for Democrat Senator Maggie Hassan and Barbara Boxer. Perhaps Mr. Cosko was also the staffer tasked with filling the envelopes Rep. Sheila Jackson Lee was spotted passing out at the Kavanaugh hearing.

Busy week for Ms. Sheila Jackson Lee and staff…

