¶1In a jury trial made subject to G. L. c. 278, §§ 33A-33G, as amended, the defendants were convicted on separate indictments charging each of them with mayhem, assault and battery by means of a dangerous weapon and armed assault with intent to commit murder. They assign as error the trial judge’s denial of their motions to inspect the minutes of the grand jury, his allowing the prosecutor to put leading questions to two of the Commonwealth’s witnesses, his denial of their motions for mistrial based on the questioning of three witnesses and his overruling of defense objections to the Commonwealth’s closing argument.
¶2There was evidence from which the jury could have found that at approximately 3:00 a.m. on September 23, 1972, Richard Paaso, the victim, with two acquaintances, Donald Maley and Dana Leahy, accompanied by a German shepherd dog belonging to a friend of Paaso, drove to a bar adjacent to the Charles River Motel on Soldier’s Field Road in Rrighton. Leaving their car, which also belonged to Paaso’s friend, in the parking lot nearby, they entered the bar and there saw the defendant John O’Master. Paaso indicated that he wished to talk to *260O’Master. The latter led him to a table where he sat between O’Master and the defendant David White. Leahy and Maley remained a few yards away; and the dog wandered among the tables of the bar. Paaso had known White for about ten years. During this period he had also become acquainted with O’Master. Paaso told the defendants that he had come to thank them for helping his friend Leahy. O’Master asked him why he was interested and if any of his money was involved. Paaso replied: “No.” Whereupon O’Master said to him, “Are you some type of tough guy?” and, “We are the power around here.” Then, without warning, O’Master reached over and “grabbed” Paaso’s ear. Paaso reached up and felt blood rushing down his face. He stood up and both defendants closed in on him. He felt “quick thrusts” in his stomach coming from White’s direction. He panicked, overturned a chair, ran from the lounge and hid in a ditch. As he was running, he noticed that O’Master struck the dog. He remained in the ditch for several minutes, and then sought assistance from Boston police.in a patrol wagon which had stopped nearby. The police drove him to a hospital. He had sustained serious injuries including cuts on his stomach, chest, face and neck. His left ear was nearly severed.
¶3Later on September 23, the mutilated body of the dog was found in the parking lot by a motel maintenance man, Bucelwicz, who, at the suggestion and with the assistance of the defendant White, removed the body of the dog to a nearby field. There it was later discovered by the dog’s owner whose car was also found in the parking lot.
¶41. In their joint brief the defendants argue that it was error for the judge to deny their motion to inspect the minutes of the grand jury.
¶5We therefore consider the defendants’ argument in light of the law prior to the Stewart case. Prior thereto, a defendant was not entitled to examine grand jury minutes as matter of right. Commonwealth v. Giaco-mazza, 311 Mass. 456, 462 (1942). A motion to permit inspection of such minutes was addressed to the discretion of the judge. Commonwealth v. Balliro, 349 Mass. 505, 518 (1965). It was deemed appropriate for the judge to review the minutes to determine whether an inconsistency existed between the witness’ testimony at trial and that given before the grand jury. Commonwealth v. Doherty, 353 Mass. 197, 209-210 (1967), cert. den. 390 U. S. 982 (1968), overruled on other grounds in Connor v. Commonwealth, 363 Mass. 572, 574 (1973). The presence of inconsistency would constitute a “particularized need” for the minutes (Commonwealth v. Carita, 356 Mass. 132, 141-142 [1969]; Commonwealth v. De Christoforo, 360 Mass. 531, 534-536 [1971]; Commonwealth v. Dominico, 1 Mass. App. Ct. 693, 709-710 [1974]), warranting their examination by defense counsel. Commonwealth v. Ladetto, 349 Mass. 237, 244-245 (1965). Commonwealth v. Abbott Engr. Inc., 351 Mass. 568, 578-579 (1967).
¶6*262Where, as here, the judge found no inconsistency between Paaso’s testimony before the grand jury and his testimony at trial, no “particularized need” for access to the minutes was shown. Commonwealth v. Kiernan, 348 Mass. 29, 36 (1964), cert. den. sub nom. Gordon v. Massachusetts, 380 U. S. 913 (1965). Commonwealth v. Dominico, supra. In addition, counsel for the defendants thoroughly explored in extensive cross-examination of Paaso and other witnesses Paaso’s initial statement, which he admitted having made, that he had been attacked by an unknown assailant. The jury’s attention was emphatically directed to the credibility of Paaso on this point. Coupled with the judge’s ruling that Paaso’s testimony at trial was “completely consistent” with that given before the grand jury, no injustice resulted to the defendants from the denial of the motion.
¶72. The defendants next contend that the prosecutor’s examination of the witness Dana Leahy was improper and that the judge erred in denying their motions for mistrial based on the alleged improper questioning of this witness.
¶8Although the judge did not formally declare Leahy to be a hostile witness until well along in the prosecutor’s examination, it was in his discretion to allow leading questions up to that point and thereafter. Commonwealth v. Coshnear, 289 Mass. 516, 527 (1935). Commonwealth v. Jones, 319 Mass. 228, 229-230 (1946). Commonwealth v. LaFrance, 361 Mass. 53, 57 (1972). In Commonwealth v. Flynn, 362 Mass. 455, 467 (1972), the court reiterated the language of Giuffre v. Cara-*263pezza, 298 Mass. 458, 460 (1937), viz., “ [W]e are aware of no decision in this Commonwealth in which exceptions have been sustained because of the allowance of leading questions.”
¶9We find no merit in the further argument of the defendants that the examination by the prosecutor violated the provisions of G. L. c. 233, § 23, in attempting to impeach Leahy’s credibility by evidence of “bad character.” A review of the testimony makes it apparent that the objective of this questioning was not to elicit evidence of Leahy’s criminal activities, but rather to have him testify to his whereabouts during and after the assault upon Paaso including his alleged return to Paaso’s apartment later that morning, and to contradict his testimony that he was in bed at home at the time of the incident. Evidence material to prove an issue in a case is not incompetent simply because it reveals criminal activity on the part of a witness. Commonwealth v. Dominico, supra, at 713. Commonwealth v. West, 312 Mass. 438, 441 (1942).
¶103. The defendants raise similar objections to the use of leading questions and the denial of their motions for a mistrial in the examination by the prosecutor of the witness Bucelwicz.
¶11*264The judge forestalled the possibility of prejudice, which might have resulted from this line of questioning, by repeatedly instructing the jury that questions to which negative answers were given were not to be considered by them. It is our rule that jurors may normally be expected to follow instructions to disregard matters withdrawn from their consideration. Commonwealth v. Bellino, 320 Mass. 635, 645 (1947), cert. den. 330 U. S. 832 (1947). Commonwealth v. Crehan, 345 Mass. 609, 613 (1963). Commonwealth v. Gordon, 356 Mass. 598, 604 (1970). Contrast Commonwealth v. Fillippini, ante, 179, 187 (1974). The record does not establish that the questions of the prosecutor were without foundation or were put in bad faith. See Commonwealth v. Granito, 326 Mass. 494, 498 (1950).
¶124. The defendants moved for a mistrial based upon the direct examination by the prosecutor of a Boston police department detective.
¶135. Finally, the defendants argue that comments by the prosecutor during closing argument were prejudicial and *265should have been struck.
¶14Certain of the prosecutor’s remarks in argument were ordered struck by the judge; and we need not consider other objections of the defendants to the argument to which appropriate exceptions and assignments of error were not taken, particularly where, as here, the record fails to reveal “a substantial risk of a miscarriage of justice.” Commonwealth v. Franks, 365 Mass. 74, 76 (1974). Commonwealth v. Foley, 358 Mass. 233, 236 (1970). The argument of the prosecutor appears to have been based upon the appearance and testimony of witnesses and the appearance of the defendants along with reasonable inferences which the jury might have drawn therefrom. The judge’s instructions made it clear to the jury that arguments were not evidence and left to the collective memory of the jury the evaluation of the testimony. It is our conclusion that under standards of permissible argument the prosecutor’s comments were not unreasonable. Commonwealth v. Velleco, 272 Mass. 94, 99 (1930). Commonwealth v. Smith, 342 Mass. 180, 187-188 (1961). Commonwealth v. Balakin, 356 Mass. 547, 550-553 (1969). Commonwealth v. Heard, 360 Mass. 855 (1971).
¶15Other assignments of error
¶16 Judgments affirmed.
¶17White’s assignment of error 4; O’Master’s assignment 2.
¶18White’s assignments of error 8-16; O’Master’s assignments 6-13.
¶19White’s assignments of error 17 and 18; O’Master’s assignments 14 and 15.
¶20White’s assignment of error 22; O’M aster’s assignment 18 and 19.
¶21White’s assignment of error 26; O’Master’s assignment 23.
¶22White’s assignments of error 1-3, 5-7, 19-21, 23-25; O’Master’s assignments 1, 3-5, 16, 17, 20-22.