An arrestee who escaped from a Northwest Washington psychiatric hospital on Monday fled through a back door of a room that law enforcement officers were barred from entering, according to the D.C. Department of Corrections.

The suspect, identified as Kenneth Clayton, who is in his early 30s and lives in Northeast, had not been captured as of late Tuesday afternoon. Police said they have issued a warrant for his arrest and that the Capital Area Regional Fugitive Task Force was assisting in the search.

D.C. police had arrested Clayton on Sunday and charged him with assault on a police officer, simple assault, making threats and possession of unregistered ammunition. Authorities said that early Monday he was taken to United Medical Center in Southeast Washington. The reason was not immediately clear.

Shortly before 2:30 a.m., the Department of Corrections said officers transferred him to the Psychiatric Institute of Washington, in the 4200 block of Wisconsin Avenue NW. After an initial screening, corrections officials said in a statement that Clayton was placed in a locked room in a restricted area. The statement says that it is a room in which “uniformed personnel are not allowed to enter nor have visual contact due to the institute’s medical privacy protocols.”

About 10:40 a.m., authorities said Clayton “fled through a back door exit of the restricted wing.” Officials would not say whether he forced open a door or it was unlocked.

The chief operating office of the psychiatric institute declined to comment on the escape. A statement from its public affairs office said only that the institute would cooperate with the investigation. Questions about security protocols were not answered, citing patient confidentiality.

Clayton is described as black, 6 feet 2 inches tall and weighing 208 pounds. He has a medium to dark complexion, tattoos on both forearms, bald head and was last seen wearing a blue T-shirt, and blue or black pants.