Mass. Gen. Laws ch. 265, § 59
(a) At any time after the entry of a judgment of disposition on an indictment or criminal or delinquency complaint for an offense under section 26, subsection (a) of section 53 or subsection (a) of section 53A of chapter 272 or under section 34 of chapter 94C for simple possession of a controlled substance, the court in which it was entered shall, upon motion of the defendant, vacate any conviction, adjudication of delinquency or continuance without a finding and permit the defendant to withdraw any plea of guilty, plea of nolo contendere, plea of delinquent or factual admission tendered in association therewith upon a finding by the court of a reasonable probability that the defendant's participation in the offense was a result of having been a human trafficking victim as defined by section 20M of chapter 233 or a victim of trafficking in persons under 22 U.S.C. 7102; provided, however, that: