making full disclosure of his interest . . . .” Relying on this language, the defendant argues that because the Commonwealth failed to show that he did not disclose his interest to the town clerk before purchasing the land — which, according to the defendant, is an element of the offense — the evidence is insufficient to establish his guilt. The argument misses the mark. Giving notice to the town clerk brings the defendant within an exception to the general prohibition against a municipal employee entering into a contract with his or her municipal employer and, in our opinion, is to be viewed as an affirmative defense. In other words, the burden is on the defendant to come forward with evidence that he gave the proper notice. Cf. Commonwealth v. Jones, 372 Mass. 403, 406 (1977) (<HOLDING>). See also G. L. c. 278, § 7; Commonwealth v.
holding of license brings person within an exception to general prohibition against carrying a firearm and is affirmative defense holding that prohibition may not be used to raise affirmative defense of workers compensation immunity holding that fair use is an affirmative defense holding that laches is an affirmative defense holding that possession of a license is an affirmative defense to a charge under g l c 269  10a