Pete Sessions

The chief of staff for Rep. Pete Sessions, a Texas Republican, was charged Wednesday with bringing a firearm into the US Capitol complex, according to court documents obtained by CNN.

Luis Angel Vega is expected to make an appearance in DC court Friday on the charges, which stem from an alleged incident in December.

Capitol security officers found the black pistol Vega allegedly carried when the staffer’s bag was run through a security checkpoint at the entrance of a House office building that’s part of the Capitol complex, the court documents said. They then instructed Vega to lock up the firearm in his car and then return for his bag to be re-screened, which he did, according to the filings.

The charging documents describe a telephone interview the DC police conducted with Vega a week after the alleged December 22 episode. Vega told the police officer that he did not have a license to carry the pistol, according to the court filings, and that usually he enters the House office building with Sessions — referred to was “Witness-1” in the documents — who is exempt from being screened by the mags.

“The day of the offense was out of the ordinary in that Witness-1 entered the building separately from the defendant and the defendant forgot there was a pistol in his bag,” the court filings said.

CNN reached out to Session’s office for comment. A lawyer for Vega has not yet been identified.

The DC Metro Police and US Attorney’s office in DC didn’t immediately return a request for comment.

Vega faces two counts: carrying a gun outside his home without a license and carrying a firearm onto the Capitol grounds.

CNN’s Ellis Kim and Holmes Lybrand contributed to this report.