¶1After a jury trial, the defendant was convicted of murder in the second degree in the shooting death of Julio Zuniga (Zuniga), in violation of G. L. c. 265, § 1, and assault and battery by means of a dangerous weapon causing serious bodily injury to Roberto Francisco Sanchez Rios (Sanchez Rios), in violation of G. L. c. 265, § lSA(c).
¶21. Background, a. The club. At approximately 11:00 p.m. on October 11, 2008, Zuniga went to a nightclub in Lawrence to watch a televised soccer game. He was accompanied by his brothers, Francisco “Paco” Zuniga (Paco) and Altero Zuniga (Altero),
¶3At 12:15 a.m. on October 12, the defendant, Frederich Frias, and Edward Rosario entered the same club. The defendant’s group arrived in a light brown Acura sedan driven by, and registered to, the defendant. The defendant’s group spent some time in the downstairs area of the club, then proceeded upstairs; Zuniga’s group was upstairs watching soccer.
¶4When the club closed at 1:00 a.m., Zuniga’s group walked to a lot across the street from the club where Paco had parked his SUV. When they got to the SUV, Zuniga told the others he wanted something to eat, and they walked back across the street to a food cart. Altero and Bolanos went back into the club. After buying some sandwiches, Zuniga and the remainder of his group walked back across the street to where the SUV was parked. When the defendant’s group left the club, they also crossed the street to an alley where the defendant had parked his Acura. The area was not well lit.
¶5b. The shootings. The Commonwealth’s three key witnesses provided varying accounts of the shootings. Sanchez Rios testified that after they bought their sandwiches and were returning *456to the SUV, he heard Frias
¶6At this point, either Rosario or the defendant pushed Sanchez Rios onto his side. As Sanchez Rios sat up, he heard two or three shots, looked at Zuniga, and heard more shots. During the second volley of shots, Sanchez Rios could see that the defendant was the shooter, as his face was illuminated by the flashes of the discharging gun.
¶7Paco testified that when he went to get the SUV in the lot across the street, he could see that it was blocked in by other cars. Paco was told that a fight had erupted, and he saw Zuniga fighting with three or four people near the defendant’s Acura. Zuniga was fighting with the defendant, Sanchez Rios, and Frias, and Rosario was hitting Estrella. Paco hit Rosario in defense of Estrella, and Rosario withdrew and walked toward the Acura. When Paco turned to help Zuniga and Sanchez Rios, Rosario resumed his beating of Estrella. Paco then chased Rosario in the direction of the Acura, and Rosario said he was done fighting. Paco heard some shots and turned around and saw a “person” with a gun. Paco heard Zuniga say something like *457“[shoot] me if you have balls,” and then the gunman fired more shots. Zuniga grabbed his chest in pain and Paco ran around the Acura towards the shooter; Rosario ran away. Paco heard more shots and saw the shooter get into the Acura and drive away at a high rate of speed. He did not see anyone else in the Acura.
¶8Frias testified that he was on his cellular telephone yelling at his girlfriend when the defendant’s group was near the Acura. Frias believed that Zuniga’s group mistakenly thought Frias was addressing them, which resulted in Zuniga’s group confronting the defendant’s group. A fight began. Frias claimed he was stomped and kicked while he was on the ground, and the defendant and Rosario abandoned him there. As Frias saw Rosario running away, he heard two shots, and then a third. Frias looked at the defendant standing next to the Acura, and Frias saw the flash of the gun as more shots were fired. Frias then saw the defendant, alone, drive away quickly; Frias ran down an alley and met up with Rosario a few blocks away.
¶9c. The defendant threatens Frias. Later that morning at 9:30 a.m., the defendant spoke to Frias on the telephone and admitted to Frias “that [the defendant] had killed somebody and he did it for” Frias. Frias denied that the defendant had done it for Frias because they were all merely fighting and the defendant unnecessarily escalated the matter by using a gun. The defendant warned Frias that if he said “anything about this,” the defendant would “send Cesar after” him. Frias knew Cesar, and Frias told the police that he was afraid of the defendant.
¶102. The defense. The main premise of the defense was misidentification.
¶11Sugeily believed the men were looking for a fight, but they told her she would not get shot because she was female. Sugeily quickly got into Vanessa’s car and moved it to the street in front of the food cart. Sugeily saw Zuniga’s group walking from the cart and saw the man in the black sweater yell at them, and a fight began with the defendant’s group. She saw Frias on the ground getting kicked by Zuniga’s group, and the man in the black sweater quickly entered and exited the car, followed by smoke and the sound of “firecrackers” coming from the passenger’s side. Frias and the man in black got into the car and drove away. Sugeily told the police that Zuniga had not been in the fight at all and was minding his own business when he got shot.
¶12The defense contended that the defendant wore a red sweater or shirt that night and the shooter wore a black sweater or black jacket. This implied that Rosario, not the defendant, was the other man Sugeily saw with Frias behind the car.
¶133. The instructions. After explaining the definition of proof beyond a reasonable doubt and in conjunction with the elements of murder in the first degree, the judge stated that to be murder, a killing must be unlawful. Further explaining, he stated:
“An unlawful killing . . . is a killing done without excuse. Now not all killings are unlawful. A killing maybe excused, for example, in the case of self-defense or defense of another. And the evidence in this case does raise the issue of whether this killing was . . . excuse[d] as a result of self-defense or the defense of another.”9
¶14The judge instructed the jury that it was the Commonwealth’s *459burden to “prove beyond a reasonable doubt that the killing was not the result of the defendant’s acts of self-defense or defense of another.”
¶15After instructing on murder and before discussing manslaughter, the judge reiterated that the jury must find an unlawful killing in order to convict the defendant of either degree of murder, and he returned to the concepts of self-defense and defense of another. He stated:
“If someone is acting in a legitimate exercise of self-defense, then they are not guilty of murder. They’re not guilty of second degree murder. They’re not guilty of manslaughter. They’re not guilty of anything, because you are entitled, in the appropriate circumstances, to use deadly force against someone, or a legitimate use of self-defense or defense of another.”
¶16The judge also reminded the jury that it was the Commonwealth’s burden to prove beyond a reasonable doubt that the defendant did not act in self-defense or defense of another.
¶17Following this, the judge instructed on self-defense, the use of deadly force, reasonable fear and apprehension of death or serious bodily injury, and again, the Commonwealth’s burden of proof as it related to these terms. In conjunction with self-defense, the judge again instructed the jury on defense of another. He stated that a killing may also be excused if it was done not in self-defense but in defense of another. Elaborating, the judge instructed that defense of another
¶18“mirrors that of self-defense, that is the Commonwealth must prove beyond a reasonable doubt that the defendant did not act in defense of a third person. If the Commonwealth fails to prove beyond a reasonable doubt that the defendant did not act in defense of a third person, then you must find the defendant not guilty. In other words, if you have a reasonable doubt about whether the defendant *460acted in defense of a third person, then your verdict must be not guilty. But again, you can only use deadly force in defense of a third person as I have already instructed you on self-defense.”
¶19The judge then turned to manslaughter and instructed as follows:
“Remember, if the Commonwealth fails to prove to you that the defendant did not act in self-defense or fails to prove to you that the defendant did not act in defense of another, as I’ve put up there on the board the appropriate use of self-defense, then the defendant is not guilty of either murder or manslaughter. But if the Commonwealth . . . fails to prove to you that the defendant did not act in self-defense but does prove to you beyond a reasonable doubt that he used excessive force in self-defense, then ... the defendant would be guilty of the lesser included crime of manslaughter.”
¶20Noting the double negatives in the instruction, the judge repeated it, stressed that the Commonwealth always bears the burden of proof, and stated:
“The Commonwealth has to prove to you beyond a reasonable doubt that the defendant was not acting in self-defense. If the Commonwealth proves to you, that he’s not acting in self-defense or defense of another, it [has] proven an unlawful killing. But if they fail to do that, if they fail to prove to you beyond a reasonable doubt the defendant was not acting in self-defense or not acting in defense of another, but do prove to you, the Commonwealth does prove beyond a reasonable doubt that the defendant used excessive force in self-defense, then the Commonwealth has proven the lesser included crime of manslaughter.”
¶21After a short break, the judge told the jury that to prove murder in either degree, the Commonwealth was required to prove malice, and that the Commonwealth had to prove the absence of “certain mitigating circumstances, . . . which lessen the defendant’s culpability for an act.” A killing “may be the crime of manslaughter” if committed “under mitigating cir*461cumstances.” The judge explained that “the circumstance that you must consider is heat of passion induced by sudden combat.” He instructed on heat of passion, but did not mention either self-defense or defense of another in his “mitigating circumstances” instructions.
¶22After instructing on the elements of armed assault with intent to murder and assault and battery by means of a dangerous weapon causing serious bodily injury, where Sanchez Rios was alleged to be the victim, the judge the jury instructed that the Commonwealth
¶23“has to prove beyond a reasonable doubt that the defendant was not acting in self-defense at the time or not acting with the appropriate use of self-defense or defense of another. The same definition I’ve already given on the murder charge.
¶24“If the Commonwealth, if you find that the Commonwealth has failed to prove that the defendant was not acting in self-defense or not acting in defense of another, or failed to prove some other mitigating circumstances, such as heat of passion induced by sudden combat, then you would go on to consider whether the Commonwealth has proven the lesser included crime of armed assault with intent to kill.
¶25“Now if there [was] evidence of mitigation, and mitigation would be, for example, acts done in self-defense or defense or another, or acts done when in sudden combat, then you would consider the issue of the lesser included crime of armed assault with intent to kill, not intent to murder.
¶26“Now . . . if . . . you determine the Commonwealth has proven beyond a reasonable doubt that the defendant assaulted Mr. Sanchez Rios while armed with a dangerous weapon, but that there were certain mitigating circumstances, such as he was acting with heat of passion, with — based on sudden combat, he would be not guilty of armed assault with intent to murder.. . .[
¶27*462“Likewise, if the Commonwealth proves to you the elements of armed assault with intent to murder but fails to prove to you beyond a reasonable doubt that the defendant was acting in self-defense or fails to prove to you beyond a reasonable doubt that he was acting in defense of another,[
¶28Relative to the charge of assault and battery by means of a dangerous weapon causing serious bodily injury, the judge instructed the jury that:
“the Commonwealth would have to prove to you beyond a reasonable doubt that the defendant was not acting in the appropriate use of self-defense or defense of another. If the Commonwealth fails to prove that, then the defendant is not guilty of assault and battery by means of a dangerous weapon causing serious bodily injury, unless the Commonwealth proves to you beyond a reasonable doubt that the defendant acted with excessive use of force in self-defense or defense of another.”
¶29After explaining the elements of assault and battery by means of a dangerous weapon causing serious bodily injury that the Commonwealth would have to prove beyond a reasonable doubt, the judge added:
“And the Commonwealth also has to prove that the battery or the touching was not justified or excused in some way. Again, that’s why I mention that they have to prove beyond a reasonable doubt that he was not acting in the legitimate use or the appropriate use of self-defense or defense of another.”
¶304. Discussion, a. The standard of review. The defendant filed *463several written requests for jury instructions, including an instruction on defense of another with language explaining that the use of excessive force in defense of another reduced the crime of murder to manslaughter. At the charge conference, the judge agreed to give a defense of another instruction, but he declined to give an involuntary manslaughter instruction or a Bowden instruction.
¶31Despite the lack of any objection to the defense of another instruction, the defendant asserts that the claims now made for the first time on appeal were preserved when the judge “saved” the defendant’s rights at the charge conference. We disagree. In general, claims may be preserved for appellate review when a party’s rights are saved. See Commonwealth v. Dunton, 397 Mass. 101, 102 n.2 (1986) (where defendant requested particular instruction before charge but did not object to judge’s refusal to give instruction after charge, issue nonetheless preserved for appellate review because judge told defense counsel that defendant’s rights “were fully protected”). Also, when a judge refuses to give a requested instruction, a defendant’s rights are saved without the necessity of a further objection. See Commonwealth v. Rosario, 460 Mass. 181, 187 (2011). However, when a judge agrees to give a requested instruction — as the judge did here with the request for a defense of another instruction — any claim of error in the adequacy of the instruction must be preserved for appellate review by a postcharge objection. See Commonwealth v. Thomas, 439 Mass. 362, 371 (2003). See also Commonwealth v. McDuffee, 379 Mass. 353, 357 (1979) (“It is *464a fundamental rule of practice that where a party alleges error in a charge he must bring the alleged error to the attention of the judge in specific terms in order to give the judge an opportunity to rectify the error, if any”). Here, the only relevant appellate rights the judge saved related to his refusal to give either a Bowden or an involuntary manslaughter instruction. Because the defendant failed to object to the defense of another instruction, the claims he now raises on appeal are not preserved. See Mass.R.Crim.P. 24(b), 378 Mass. 895 (1979). We therefore review to determine whether an error occurred and, if so, whether that error created a substantial risk of a miscarriage of justice.
¶32To determine whether the judge’s instruction created a substantial risk of a miscarriage of justice, and keeping in mind that “[ejrrors of this magnitude are extraordinary events and relief is seldom granted,” Commonwealth v. Randolph, 438 Mass. 290, 297 (2002), we ask four questions. They are: “(1) Was there error? (2) Was the defendant prejudiced by the error? (3) Considering the error in the context of the entire trial, would it be reasonable to conclude that the error materially influenced the verdict? (4) May we infer from the record that counsel’s failure to object or raise a claim of error at an earlier date was not a reasonable tactical decision?” Id. at 298 (citations omitted). “Only if the answer to all four questions is ‘yes,’ may we grant relief.” Ibid.See Commonwealth v. Russell, 439 Mass. 340, 345 (2003).
¶33In Commonwealth v. Martin, 369 Mass. 640, 649 (1976), the Supreme Judicial Court stated the elements of defense of another as follows: “An actor is justified in using force against another to protect a third person when (a) a reasonable person in the actor’s position would believe his intervention to be necessary for the protection of the third person, and (b) in the circumstances as that reasonable person would believe them to be, the third person would be justified in using such force to protect himself.” Here, the defendant claims the judge failed to communicate to the jury the substance of defense of another and only paraphrased the second paragraph of the Model Jury Instructions on Homicide 57 (1999) by stating that “the Commonwealth must prove beyond a reasonable doubt that the defendant did not act in defense of a third person.” The defendant *465argues this instruction was vague, it did not tell the jurors that the defendant had the right to use deadly force to defend Frias if Frias had the same right, and the judge did not explain that the defendant’s conduct had to be considered through the lens of a reasonable person.
¶34Our review of claimed jury instruction errors requires us to “evaluate the instructions as whole, looking for the interpretation a reasonable juror would place on the judge’s words.” Commonwealth v. Trapp, 423 Mass. 356, 361, cert, denied, 519 U.S. 1045 (1996). “We do not consider bits and pieces of the instructions in isolation.” Commonwealth v. Young, 461 Mass. 198, 207 (2012).
¶35The defendant first claims the judge’s instruction was not specific enough regarding the definition of defense of another and that the judge failed to instruct that the defendant had the right to use deadly force if Frias had the same right under the circumstances. While the judge did not define defense of another or use the Martinfactors verbatim, see Commonwealth v. Martin, 369 Mass, at 649, it would have been improper for him to have given the “alter ego” instruction the defendant has now raised on appeal. In the second clause of the Martinformulation, “the circumstances must be viewed from the perspective of the intervening defendant, not of the third party.” Commonwealth v. Young, supra at 209. See Commonwealth v. Martin, supra.“Thus, whether [Frias] was, in retrospect, actually entitled to use self-defense is not a consideration.” Commonwealth v. Young, supra.Relative to whether the jury were instructed to consider the defendant’s conduct under a reasonable person standard, we do not find fault in the judge’s instruction. Although he did not use the Martinformulation verbatim, the judge did refer to actions, *466fear, and apprehension in terms of reasonableness.
¶36The defendant next claims the judge failed to charge the jury that the use of excessive force in the defense of another may serve as a mitigating factor to reduce murder to manslaughter. When the charge is evaluated as a whole, we disagree. The judge instructed the jury that both degrees of murder required the Commonwealth to prove an unlawful killing, and that a killing was deemed “excused” or “not unlawful” if it occurred in the defense of another. He repeated this in his instructions on self-defense and defense of another, where he stated that the defendant was not guilty of any crime if he acted in the “legitimate use” of defense of another. He further noted that defense of another “mirrors” self-defense. This was a correct statement of the law. See Commonwealth v. Martin, supra at 650 (“[T]he trend . . . has been to interweave closely the justification of defense of a third person with self-defense”); Commonwealth v. Adams, 458 Mass. 766, 774 (2011) (“Defense of another tracks, and is interwoven with, the elements of self-defense”); Model Jury Instructions on Homicide 58 (1999) (“The defense of another instruction should mirror the self defense instruction”).
¶37On the subject of excessive force, the judge twice stated that the use of such force in self-defense reduced murder to manslaughter. Although he did not specify the same for defense of another at this point in the charge, he did speak of self-defense in tandem with, or the equivalent of, defense of another. A similar, nonfatal slip occurred in Commonwealth v. Clemente, 452 Mass. 295, 322 (2008), where the judge mistakenly told the jury that a defendant loses his justification completely when he *467uses excessive force in defense of another. Because of this, the defendant claimed the judge failed to inform the jury that excessive force in defense of another required a manslaughter verdict and precluded a murder conviction. Ibid.However, the Supreme Judicial Court concluded that because the judge had properly explained the excessive force concept within his instruction on self-defense, which in context applied equally to defense of another, there was little chance the jury failed to realize the import of excessive force. Id. at 323. The same is true here where the judge explicitly told the jury that the two defenses mirrored one another and functioned as equivalents.
¶38In addition, the import of excessive force was made clear when the judge discussed mitigating circumstances that reduced murder to manslaughter. Although he initially spoke in terms of heat of passion and sudden combat, the judge treated self-defense and defense of another equally when he instructed on armed assault with intent to murder Sanchez Rios and assault and battery by means of a dangerous weapon causing serious bodily injury to Sanchez Rios. The judge specifically instructed that if the Commonwealth “failed to prove that the defendant was not acting in self-defense or not acting in defense of another, or failed to prove some other mitigating circumstance, such as heat of passion induced by sudden combat,” then the jury were to consider whether the Commonwealth had proved the lesser included offense of armed assault with intent to kill. He further told the jury that self-defense and defense of another are examples of mitigating circumstances. While these instructions were given in the context of armed assault with intent to murder, the judge coupled self-defense and defense of another as mitigating circumstances. When this is combined with the previous instruction on excessive force and manslaughter, a reasonable juror would properly understand that the use of excessive force in defense of another reduced murder to manslaughter.
¶39When the instructions are considered as a whole, and not *468parsed out in isolation, we conclude that the defendant’s claims are without merit. However, even if we were to conclude the definition of defense of another was not specific enough, or failed to properly track the Martinformulation, 369 Mass, at 649, or failed to explain the mistaken use of deadly force, we could not conclude that the defendant suffered any real prejudice or that the error materially influenced the verdict.
¶40Assuming the defendant was entitled to the defense of another instruction, the defenses advanced at trial were misidentification, that Rosario was the shooter, and that there was shoddy police work. These were the theories provided by the defendant in his opening statement
¶41All these factors belie any claim by the dissent that intent and defense of another were either contested or live issues. Even though we must evaluate the claimed instructional error for the effect it would have on a reasonable juror, see Commonwealth v. Trapp, 423 Mass, at 361, that task is not carried out in a vacuum but against the backdrop of the trial that actually occurred. Here, a reasonable juror would have no knowledge of the contest the dissent creates, because it did not take place.
¶42Judgments affirmed.
¶43The jury acquitted the defendant of armed assault with intent to murder.
¶44We refer to Zuniga’s brothers, and certain other witnesses, by their first names or nicknames to avoid confusion.
¶45Sanchez Rios testified that the comment came from the thin man in the defendant’s group. Frias was described as “slim” and the defendant and Rosario were described as “husky” and “stocky.”
¶46Sanchez Rios identified the defendant in a photographic array and at trial. Sanchez Rios remarked that he had seen the defendant’s face and would never forget the face of the man who shot him.
¶47The presence of gunshot residue on Sanchez Rios indicated that he was shot from a range of two feet or closer.
¶48The area of Zuniga’s wounds tested negative for gunshot residue, which indicated that he was not shot at close range.
¶49The defendant also contested the adequacy of the police investigation. See Commonwealth v. Bowden, 379 Mass. 472, 485-486 (1980).
¶50Although various witnesses described the car as being different colors and models, based on the location the jury could reasonably have concluded that the car was the defendant’s Acura.
¶51Later, relative to murder in the second degree, the judge again instructed that the Commonwealth had to prove “an unlawful killing . . . that is killing that was not done in self-defense, or a killing that was not done in defense of another.”
¶52To assist in his jury charge, the judge used a blackboard that contained instructions on identification and the elements of murder, including that the Commonwealth must prove an unlawful killing, which in turn required the Commonwealth to prove that the defendant did not act in self-defense or in defense of another. The defendant did not lodge an objection to the use of the blackboard or to the contents of the instructions written upon it.
¶53The judge repeated this instruction twice.
¶54The judge did not include the word “not” before both uses of the word “acting” in this clause. Similarly, while explaining the verdict slip and manslaughter, the judge spoke in terms of the Commonwealth’s burden to prove self-defense or defense of another, as opposed to failing to prove the defendant did not act in self-defense or defense of another.
¶55See note 7, supra.
¶56The defendant also claims that the judge failed to instruct on the mistaken use of deadly force, but he only requested this instruction in conjunction with self-defense. The judge was not required to further expound on the concept without a request to do so.
¶57The defendant claims that we should review for “possible misunderstandings by reasonable jurors” to determine if there was error. However, that standard only applies to instructional errors that lowered the Commonwealth’s burden of proof as to the elements of the offense. See Commonwealth v. Smith, 427 Mass. 245, 249 n.6 (1998); Commonwealth v. Medina, 430 Mass. 800, 804 n.4 (2000).
¶58For example, the judge told the jury that a person is “entitled, in the appropriate circumstances, to use deadly force against someone” in defense of another. He further told the jury of the circumstances in which the use of deadly force in self-defense was permissible, i.e., when a person has a “reasonable apprehension of great bodily harm or death and a reasonable belief that no other means would suffice to prevent such harm” (emphasis supplied).
¶59After warning about the danger of speculation, the dissent maintains that when the jury were properly instructed on excessive force in defense of another in relation to the charge of assault with intent to murder, they acquitted the defendant of that charge. However, the dissent’s conjecture glosses over the facts that this was a different charge and a different victim.
¶60In his opening statement, the defendant maintained that this case was “simple” because he shot neither the victim nor Sanchez Rios. He instead claimed that Rosario, wearing a black shirt, was the shooter and that the Commonwealth would fail to prove the defendant shot anyone.
¶61In his closing argument, the defendant marshalled the evidence to argue that the Commonwealth had failed to prove that the defendant shot anyone, as he had told the jury in his opening statement. He further argued that Rosario had a motive to shoot the victim because he was protecting Frias, who was Rosario’s first cousin.
¶62The dissent claims the Commonwealth introduced evidence that the defendant acted in defense of Frias which, if believed, was probative of intent and *469defense of another. See post at 480. However, a reasonable juror would not have held such a belief. The evidence in question came from Frias himself when he disputed the defendant’s contention that the defendant killed the victim for Frias, in what had merely been a weaponless street fight. Frias added that the defendant threatened him if he “said anything about” their conversation. Conveying such a threat would not have increased, in the mind of a reasonable juror, the credibility of the defendant’s claim that he acted in defense of Frias. Indeed, it suggests the idea was completely manufactured. Finally, the unreasonable nature of such a belief would have also been reinforced by the defendant’s closing argument where he argued that “no one should have been shot. No one. No one should have suffered. It was a fist fight. No one should have died, absolutely.”