Va. Code § 37.2-828
The Commissioner is authorized to enter into a contract with the United States, through the Director of the United States Bureau of Prisons or other authorized agent of the United States, for the reception, maintenance, care, and observation in state facilities, or in those designated by the Commissioner for the purpose, of any persons charged with a crime in the courts of the United States sitting in Virginia and committed by the courts to the state facilities for those purposes. All persons so admitted shall remain subject to the jurisdiction of the court by whom they were committed, and they may be returned to that court at any time for hearing or trial.
Any such contract shall require that the United States remit to the State Treasurer for each prisoner admitted specified per diem or other payments, or both, with such payments fixed by the contract.
The director of any state facility to which a prisoner of the United States is admitted shall observe the person and, as soon as possible, report in writing to the court by which he is certified or committed as to his mental condition or other matters as the court may direct.
No contract made pursuant to this section shall obligate the Commonwealth or the Commissioner to receive a federal prisoner into any state facility in which all available beds are needed for persons otherwise admitted, or in any other case where, in the opinion of the director, the admission of the prisoner would interfere with the care and treatment of other persons admitted or with the proper administration of the state facility.
Va. Code § 37.2-828