N.J. Stat. Ann. § 24:3-4

At the time of the delivery or taking of the sample excepting in the case where the article is a device, it shall be divided in the presence of the person of whom the request or demand was made, or before a witness, into two or more parts and each part shall be sealed in a suitable package. One part shall be tendered and, if accepted, shall be delivered to the person of whom the request or demand was made with a statement in writing that such sample is taken for the purpose of examination, issued in the name of the department and signed by the person taking the same.