¶1Charged with possession of a firearm without a license (G. L. c. 269, § 10[a]), the defendant moved to suppress a handgun which he is alleged to have discarded while being pursued by a Boston police officer. A Juvenile Court judge allowed the motion, concluding that the police did not have reasonable suspicion to pursue the defendant and, therefore, violated his rights under art. 14 of the Massachusetts Declaration of Rights. The Commonwealth appeals. We reverse.
¶2*117We review according to the standard recited in Commonwealth v. Moon, 380 Mass. 751, 755-756 (1980), and summarize the undisputed material facts found by the judge. A Boston police officer, working alone in a marked cruiser in the Dorchester area of that city, heard three radio transmissions beginning at about 12:25 a.m., on June 26, 1996, reporting that a fight was in progress at Winter and Church Streets in Dorchester involving three men, one with a firearm; that shots were fired; and that someone was being attacked by a dog. The officer arrived at Winter Street shortly thereafter
¶3“[N]ot every encounter between a law enforcement official and a member of the public constitutes an intrusion of constitutional dimensions requiring justification.” Commonwealth v. Stoute, 422 Mass. 782, 789 (1996). The officer’s approach without any direction to stop, coincident with his asking first the three males, and then the defendant a second time, to talk to him, did not constitute a seizure. See Commonwealth v. Sanchez, 403 Mass. 640, 644-645 (1988); Commonwealth v. Fraser, 410 Mass. 541, 543-544 (1991); Commonwealth v. Stoute, supra at 789-790. Moreover, even though the encounter involved two uniformed officers who arrived in marked cmisers, “we look to circumstances beyond the show of governmental authority inherent in the mere presence of the police . . . [for] ‘circumstances that might indicate a seizure, even where the person did not attempt to leave.’ ” Commonwealth v. Pimentel, 27 Mass. App. Ct. 557, 560 (1989), quoting from United States *118v. Mendenhall, 446 U.S. 544, 554 (1980). See 4 LaFave, Search and Seizure § 9.3(a) (3d ed. 1996 & Supp. 1998). This record contains no evidence of any intimidating or assertive conduct of the officers prior to the defendant running off which might convert an investigative encounter into a freedom restricting seizure. “In the absence of some such evidence, otherwise inoffensive contact between a member of the public and the police cannot, as a matter of law, amount to a seizure of that person.” United States v. Mendenhall, supra at 555.
¶4Assuming that a seizure (or stop) occurred when the officer commenced his pursuit of the defendant, see Commonwealth v. Stoute, supra at 789, we turn to the question of whether the requisite reasonable suspicion existed at that time. “In determining whether an officer acts reasonably in initiating a threshold, or investigatory, stop, we view the circumstances as a whole, see Commonwealth v. Williams, [422 Mass.] 111, 116 (1996), and consider the ‘specific reasonable inferences which [the officer] is entitled to draw from the facts in light of his experience.’ Terry v. Ohio, [392 U.S. 1, 27 (1968)].” Commonwealth v. Stoute, supra at 790. “[A] police officer may stop an individual and conduct a threshold inquiry if the officer reasonably suspects that such individual has committed, is committing, or is about to commit a crime.” Commonwealth v. Mercado, 422 Mass. 367, 369 (1996). That suspicion must be based on specific articulable facts and reasonable inferences drawn from them. Ibid.See Commonwealth v. Harkess, 35 Mass. App. Ct. 626, 628 (1993).
¶5While the radio reports conveyed no particularized descriptions of the three men or the dog involved, the officer’s sighting of three males, one carrying a pit bull dog, close by the area where the shooting was reported, and with no one else on the street at that late hour, reasonably supports a conclusion that they were persons possibly involved in the reported incidents.
¶6The crimes which the reports reasonably may have reflected include assault, assault with a dangerous weapon, and discharging a firearm within five hundred feet of a dwelling or other building. See G. L. c. 269, § 12E. Also, the possession of a firearm by a minor may be viewed as presumptively illegal. See Commonwealth v. Grinkley, 44 Mass. App. Ct. 62, 70 n.10 (1997). Here, the contemporaneous reports were of actual assault and gun fire. Contrast Commonwealth v. Alvarado, 423 Mass. 266, 270-271 (1996) (no justification for reasonable suspicion of criminal conduct in mere report of the carrying of a concealed weapon).
¶7We need not decide whether the radio reports coupled with the officer’s initial observations may have been sufficient, standing alone, to justify a seizure because the defendant’s unprovoked flight, as distinguished from a refusal to respond or a resumption of his walk, considered with the other circumstances, certainly tipped the scale of justification at that point, giving rise to reasonable suspicion and a right to pursue. See Commonwealth v. Sanchez, 403 Mass, at 646; Commonwealth v. Mercado, 422 Mass. at 371; Commonwealth v. Stoute, 422 Mass. at 791. See also Commonwealth v. Wren, 391 Mass. 705, 708 n.2 (1984); Commonwealth v. Harkess, 35 Mass. App. Ct. at 630-632; 4 LaFave, Search and Seizure § 9.4(f).
¶8Order granting motion to suppress reversed.
¶9The officer, the only witness at the suppression hearing, testified he arrived at Church and Winter Streets at “roughly” 12:30 a.m.
¶10Tapes of the radio transmissions, based on several calls to police 911 operators, were reviewed at the motion hearing in this case. Compare Commonwealth v. Cheek, 413 Mass. 492, 494-495 (1992); Commonwealth v. Berment, 39 Mass. App. Ct. 522, 526 (1995). There is no dispute about the reliability of the information conveyed by them, which, in any event, concerned events in progress or which had occurred recently. See United States v. Bold, 19 F.3d 99, 102 (2d Cir. 1994) (“Reasonable suspicion depends upon both the content of the information possessed and its degree of reliability”).