
    Jason D. Clairmont vs. Commonwealth.
    August 15, 1997.
    
      Supreme Judicial Court,
    
    Appeal from order of single justice. Practice, Criminal, Interlocutory appeal.
    The petitioner (defendant), who had sought relief from an interlocutory ruling of a District Court judge denying a motion to disclose informant, now appeals to the full court under S.J.C. Rule 2:21, 421 Mass. 1303 (1995), from a single justice’s denial of relief under G. L. c. 211, § 3.
    The case was submitted on the papers filed, accompanied by a memorandum of law.
    
      Robert J. Carnes for the plaintiff.
   The defendant contends that the District Court judge erred in denying the motion because the informant had exculpatory information regarding the defendant’s claim of entrapment. We review interlocutory rulings in criminal cases only in the most exceptional circumstances. Gilday v. Commonwealth, 360 Mass. 170, 171 (1971). The defendant must show that he has a substantial claim that an important substantive right of his is being violated, and that the error is irreversible. Costarelli v. Commonwealth, 374 Mass. 677, 679 (1978). Unlike one who demonstrates infringement of his right to be free from being placed twice in jeopardy (id. at 680), the defendant here could be returned to the “statu quo” through the normal process of appeal. Hence, the defendant has not made the required showing under rule 2:21 (2) that review “cannot adequately be obtained on appeal. . . or by other available means.”

Judgment affirmed.  