The Attorney General may release an alien described in paragraph (1) only if the Attorney General decides pursuant to section
3521 of title
18 that release of the alien from custody is necessary to provide protection to a witness, a potential witness, a person cooperating with an investigation into major criminal activity, or an immediate family member or close associate of a witness, potential witness, or person cooperating with such an investigation, and the alien satisfies the Attorney General that the alien will not pose a danger to the safety of other persons or of property and is likely to appear for any scheduled proceeding. A decision relating to such release shall take place in accordance with a procedure that considers the severity of the offense committed by the alien.