D.C. Code § 24-502

Any person while serving sentence of any court of the District of Columbia for crime, in a District of Columbia penal institution, and who, in the opinion of the Director of the Department of Corrections of the District of Columbia, is mentally ill, shall be referred by such Director to the psychiatrist functioning under § 24-306, and if such psychiatrist certifies that the person is mentally ill, this shall be sufficient to authorize the Director to transfer such person to a hospital for the mentally ill to receive care and treatment during the continuance of his mental illness.