When instances are reported to the United States Attorney of offenses committed on land or in buildings occupied by agencies of the Federal government -- unless the crime reported is a Federal offense regardless of where committed, such as assault on a Federal officer or possession of narcotics -- the United States has jurisdiction only if the land or building is within the special territorial jurisdiction of the United States.
PRACTICE TIP: A convenient method of determining the jurisdictional status is to contact an appropriate attorney with the agency having custody of the land. If the land is other than a military base, the regional counsel's office of the General Services Administration usually has the complete roster of all Federal lands and buildings in its region and can frequently provide a definitive answer to jurisdiction. If the land in question is part of a military base, contact with the post Staff Judge Advocate may be helpful. If the military personnel in the field or the field attorneys of the agency having responsibility for the land are unable to render assistance, the Office of Enforcement Operations of the Criminal Division should be called. Each United States Attorney would be well advised to request from each agency within the district a report on the jurisdictional status claimed for each of its facilities and assurance that documentation is available.
[cited in USAM 9-20.100]