R.I. Gen. Laws § 21-2-56: Taking of samples in investigation of violations.

No person, firm, or corporation, nor the employee of any person, firm, or corporation, shall be liable to prosecution under the provisions of this chapter if the prosecution is based upon samples of milk, unless samples of milk or cream upon which the prosecution is based are taken upon his or her premises or while in his or her possession or under his or her control by an inspector of milk or a collector of samples of milk of some city or town or an employee of the state department of health, and a sealed sample of it is given to him or her.