R.I. Gen. Laws § 42-1-2: Jurisdiction of state — Lands ceded to United States.

The jurisdiction of the state shall extend to, and embrace, all places within the boundaries thereof, except as to those places that have been ceded to the United States, or have been purchased by the United States with the consent of the state. Provided, however, with respect to all land, the jurisdiction over which shall have been ceded to the United States by the state of Rhode Island, the state of Rhode Island shall have and hereby does retain concurrent jurisdiction with the United States of and over that land, for the sole and only purpose of serving and executing thereon civil and criminal process issuing by virtue of and under the laws and authority of the state of Rhode Island.