R.I. Gen. Laws § 11-47-44: Standard of proof under §§ 11-47-42 and 11-47-43.

No negative allegation of any kind need be averred or proved in any complaint under §§ 11-47-42 and 11-47-43, and the possession of any blackjack, slungshot, billy, sandclub, sandbag, metal knuckles, bludgeon, dirk, dagger, stiletto, or other similar weapon designed to cut and stab another, and the carrying or use of any the instrument or weapons or of any of the instruments or weapons forbidden by § 11-47-42 to be carried, worn, or used shall be evidence that the possession, use, wearing, or carrying, as the case may be, of any the instrument or weapon, is unlawful, but the respondent in any the case may show any fact that would render the possession or use, or wearing or carrying of the instrument or weapon lawful.