On May 10, 1979, the defendant appeared with counsel for trial in a District Court on complaints charging him with carrying a firearm (a handgun) under his control in a vehicle without being properly licensed, unlawful possession of a hypodermic syringe, receiving stolen property (the handgun) and larceny under $100. All of these offenses were within the final jurisdiction of the District Court. After a hearing, the District Court judge allowed the defendant’s motion to suppress and dismissed three of the charges. The judge found probable cause on the fourth charge, larceny under $100, and bound over the defendant to the Superior Court.
The defendant was thereafter indicted in the Superior Court on all four charges. The defendant filed a motion to *356dismiss the four indictments, claiming that he had previously been placed in jeopardy by virtue of the District Court proceedings. On November 20, 1979, the Superior Court judge allowed the motion to dismiss, from which ruling the Commonwealth now appeals.
The pertinent facts may be summarized briefly. On February 21, 1979, the Concord police received a complaint regarding a stolen tennis racquet, along with a description of the person and the vehicle involved. Shortly thereafter the police observed the defendant’s vehicle1 and discovered a tennis racquet, matching the description given, in the rear seat.
The defendant was placed under arrest and taken to the Concord police station. The defendant’s vehicle was also towed to the station, whereupon an “inventory search” was conducted. As a result of the search, the police discovered the handgun and the hypodermic syringe.
The Commonwealth argues that the allowance of the defendant’s motion to dismiss was error because the defendant was not twice placed in jeopardy for the same offenses. We disagree.
We agree with the result and reasoning of the Superior Court judge and concur in his finding that the District Court judge did not indicate at the outset, as he was required to do, whether the hearing was a trial on the merits or was merely for the purpose of determining probable cause. If we were to accept the Commonwealth’s characterization of the proceedings in the District Court, we would be creating a hybrid process, one neither to determine probable cause nor to decide the merits.2 See Corey v. Commonwealth, 364 Mass. 137, 141-142 n.7 (1973); Commonwealth v. Clemmons, 370 Mass. 288, 290-291 (1976).
*357It is well settled that, in order for jeopardy to attach, a trial on the merits must have begun. Id. It is equally clear that a District Court judge is now “required to announce whether he [is] conducting a probable cause hearing or a full trial on the merits before the hearing commence[s].” Commonwealth v. Crosby, 6 Mass. App. Ct. 679, 681-682 (1978), citing Corey v. Commonwealth, supra, and Commonwealth v. Clemmons, supra. Where there is no indication at the outset that the judge was considering declining jurisdiction, “we must infer that the judge intended to exercise jurisdiction.” Commonwealth v. Clemmons, 370 Mass. at 291.
Although the District Court judge in the present case announced that he would dismiss three of the charges and decline jurisdiction on the larceny charge, it was not until the conclusion of the proceedings that he so indicated. A judge must at the outset “unambiguously manifest his intention to decline jurisdiction.” Commonwealth v. Crosby, supra at 683. On this record, there was no “indication that the [District Court judge] was declining jurisdiction sufficient to put this case beyond the reach of Clemmons.” Id. at 682.
In addition to the District Court judge’s failure to state unambiguously his intention to decline jurisdiction, it can be readily inferred from the conduct of the judge and both counsel in the course of the proceedings that the District Court had retained jurisdiction,3 that what might have appeared to be a suppression hearing was in fact from the outset a hearing on the merits combined with a hearing on the motion to suppress,4 and that there was no present intention to transfer the case to the Superior Court. At one point, the assistant district attorney responded in the affirmative to *358the judge’s direct and specific question whether he should “take jurisdiction.” Examples of other record evidence are that (1) the assistant district attorney indicated in open court at the outset of the hearing that this is not “a Superior Court case”; (2) both counsel agreed that the motion would be dispositive of the case;5 and (3) the judge held an evidentiary hearing at the conclusion of which he dismissed three of the complaints.6 This and other conduct of the participants7 in the District Court proceedings is consistent with the conclusion that the proceeding was a hearing on the merits. It is disingenuous for the Commonwealth to denominate otherwise such a hearing. Accordingly, because the District Court judge had begun to hear evidence before announcing the nature of the proceeding, we conclude that there was a trial on the merits. Commonwealth v. Crosby, 6 Mass. App. Ct. at 683. Commonwealth v. Clemmons, 370 Mass. at 291. See also Serfass v. United States, 420 U.S. 377, 388 (1975).
In sum, we agree with the Superior Court judge that jeopardy attached at the District Court proceeding and that the defendant, if put to trial anew, would be twice placed in jeopardy for the same offenses. Commonwealth v. Crosby, supra. Serfass v. United States, supra.
No question of “manifest necessity” or the “ends of public justice” is presented by the circumstances here. Commonwealth v. Crosby, supra. See Illinois v. Somerville, 410 U.S. 458, 459 (1973); Commonwealth v. Clemmons, supra at 292.
*359As we have decided this case on double jeopardy grounds, we need not reach the defendant’s due process claim. However, it cannot be gainsaid that it would not be fair for the Commonwealth to play “heads I win, tails you lose” with defendants in such circumstances. See note 2, supra.
Order dismissing indictments affirmed.