Mont. Code Ann. § 16-6-207

In any prosecution under this code or the rules adopted to implement this code, production by a police officer, constable, inspector, or peace officer of a certificate or report signed or purporting to be signed by a United States or state analyst as to the analysis or ingredients of any alcoholic beverage or other fluid or any preparation, compound, or substance, the certificate or report is prima facie evidence of the facts stated in the certificate or report and of the authority of the person giving or making the certificate or report without any proof of appointment or signature.