A government shutdown may disrupt the revocation of security clearances for those with dangerous mental illness, including the mechanism which could have prevented shooter Aaron Alexis from entering the Navy Yard in Washington, D.C., this September.

The Pentagon’s Central Adjudication Facility decides whether individuals are granted or denied security clearances, and is staffed largely by civilian employees vulnerable to furloughs if the government fails to pass a spending bill by midnight Monday. CAF is also responsible for revoking security clearances under certain circumstances, such as mental illness or following a criminal incidents.