The motion judge allowed the defendant’s motion and dismissed the complaint. The Commonwealth appealed from the dismissal. G. L. c. 278, § 28E. We granted the Commonwealth’s application for direct appellate review.

After the appeal was transferred to this court, we issued our decision in Commonwealth v. Forte, 423 Mass. 672 (1996). We held that sentences to the departmental disciplinary unit of a State prison did not bar, on double jeopardy ground, the subsequent criminal prosecutions of the defendants in that case for the same offenses. Our analysis in that case is controlling here. The segregation unit involved in this case, like the disciplinary unit in Forte, serves deterrent and remedial purposes, as the motion judge expressly noted, in addition to a punitive purpose. Furthermore, “assuming, without deciding, that prison discipline, at least under some extreme circumstances, may invoke double jeopardy principles,” this is hardly a case where the defendant has demonstrated on “the clearest proof’ that the sanctions imposed by the officials at the jail were “so extreme in purpose or effect as to be equivalent to a criminal penalty.” See id. at 677-678.

The order dismissing the complaint is vacated. The case is remanded to the Boston Municipal Court.

So ordered.