19 CFR § 122.102
Inspection of baggage in transit
July 16, 2020
(a) General baggage in transit may be inspected upon arrival, while in transit, and upon exportation. Carriers shall present in-transit baggage for inspection at any time found necessary by the port director.
(b) In-transit baggage shall be presented to a Customs officer for inspection and clearance before the baggage can be delivered to a passenger while in the U.S.