(concurring). I agree with the court that the judge was not required to instruct the jury on the defense of necessity. I write separately for two reasons.
First, I reiterate my concern (not implicated by the facts of this case) that evidence of necessity not be excluded by a motion in limine once a defendant has made a sufficient offer of proof. See Commonwealth v. Brogan, ante 169, 179 (1993) (Liacos, C.J., concurring); Commonwealth v. Hood, 389 Mass. 581, 596 (1983) (Liacos, J., concurring). Even though a defendant ultimately may not be entitled to an instruction on the necessity defense, the presentation of evidence regarding necessity allows the jury to fulfil their vital functions of “temper [ing] the application of strict rules of law by bringing the common sense judgment of a group of laymen to the case [and] stand [ing] as a check on arbitrary enforcement of the law” (footnote omitted). Commonwealth v. Hood, supra at 597 (Liacos, J., concurring).
*843Second, although the harm at issue here is “nonimminent” and “debatable” for purposes of the defense of necessity, the overwhelming and uncontroverted expert evidence presented at trial describing the effectiveness of needle exchange programs in curbing the spread of AIDS will, I hope, indicate to the Legislature the importance of joining the vast majority of jurisdictions that have decriminalized possession and distribution of hypodermic syringes. In the words of Dean Roscoe Pound: “Law must be stable, and yet it cannot stand still.” R. Pound, Interpretations of Legal History 1 (1923).