US Capitol police block a street during an investigation of a possible bomb threat near the US Capitol and Library of Congress in Washington, DC, on August 19, 2021.
CNN  — 

A North Carolina man pleaded guilty Friday to threatening to use explosives during a four-hour standoff with police in 2021 outside the Library of Congress near the US Capitol in Washington, DC.

Floyd Ray Roseberry, 52, faces up to 10 years in prison when he is sentenced in June, the Department of Justice said in a news release.

In August 2021, Roseberry parked outside the Jefferson building of the Library of Congress and threatened to detonate a bomb, according to court documents. FBI and local police responded to the threat, and found Roseberry, claiming to have a detonator, inside a black pickup truck with no license plates.

Roseberry also posted a livestream of himself on Facebook, telling passersby to clear the area and speaking about a “revolution.” The video and Roseberry’s Facebook profile have since been removed.

The incident prompted authorities to evacuate several buildings in the area. Officials later said that while Roseberry did possess suspected bomb-making material in his truck, the device was not capable of detonating.

This summer, a federal judge, in consultation with medical professionals, released Roseberry from jail after determining that he was suffering side effects from improper medication at the time of the incident.

His lawyers have said in court documents that Roseberry suffers from mental health issues, and was prescribed two medications by his primary care doctor at the time of the incident. The two medications can have adverse side effects when taken together and could cause manic and psychotic episodes, a psychologist who evaluated Roseberry told the court.