On February 17, 2010, a jury in the District Court convicted the defendant, Alessandro M. Marinho, and a codefend-ant, Justin Parietti, each of one count of assault and battery causing serious bodily injury pursuant to G. L. c. 265, § 13A (b). The defendant was acquitted of assault and battery with a dangerous weapon pursuant to G. L. c. 265, § 15A (b).1 He was sentenced to two and one-half years in a house of correction, nine months to serve with the balance suspended.
The defendant filed a motion for a new trial pursuant to Mass. R. Crim. P. 30 (b), as appearing in 435 Mass. 1501 (2001), alleging ineffective assistance of counsel for his lawyer’s failure (1) to advise him of the immigration consequences of an assault and battery conviction, (2) to explore a plea resolution, and (3) to advocate for a sentence that might have mitigated such immigration consequences. The motion was denied following a nonevidentiary hearing. The defendant filed timely appeals from both the conviction and the denial of his motion for a new trial. We transferred the case here on our own motion.
The defendant alleges error in (1) the denial of his motion for a required finding of not guilty; (2) the denial of his motion to dismiss based on the loss of exculpatory evidence; (3) the judge’s failure to instruct the jury on multiple defendants; and (4) the denial of his motion for a new trial.2 We affirm the conviction and the order denying the defendant’s motion for a new trial.
1. Background. The jury could have found the following facts. See Commonwealth v. Latimore, 378 Mass. 671, 677 (1979). We reserve other details for discussion of specific issues.
*117On December 22, 2008, Sam Scherer and his girl friend, Jessica Cardinal, were at Cardinal’s apartment in Wellfleet. Cardinal shared the apartment with Parietti, who lived in an upstairs room. In Parietti’s room was a television that another man, Zack Store, owned and had left in the apartment.
That evening, Store went to the apartment and had a discussion with Scherer in which Store agreed to sell the television to Scherer. Store and Scherer retrieved the television from Parietti’s room and installed it in the living room. Store left the apartment.
Shortly thereafter, Parietti arrived at the apartment with two friends, the defendant and Hunter Carwile. After Parietti saw that the television was no longer in his room, he and Scherer stepped outside and a physical fight ensued. Testimony about the particulars of the fight differed. Suffice it to say that the two men fell to the ground with Scherer positioned on top of Parietti.3 Parietti began making choking sounds. The defendant entered the fray when Scherer was still on top of Parietti, and he began to fight Scherer. After the fight, Scherer was brought to Cape Cod Hospital but then was transported to Beth Israel Deaconess Medical Center. He had a fractured nose, cheekbones, and orbital (eye socket) bones. As a consequence of the fight, Scherer had reconstructive surgery on his face. His vision was affected by the altercation; he had double vision for three to four months after the assault, and his vision at the time of trial had not been restored to normal. The defendant is not a United States citizen and was in the United States illegally. At the time of this appeal, the defendant had been deported.
2. Motion for a required finding of not guilty. The defendant contends that the judge erred in denying his motion for a required finding of not guilty. Specifically, he argues that the evidence was insufficient to establish that (1) Scherer’s injuries were “serious” within the meaning of G. L. c. 265, § 13A (b) (i), and (2) the defendant caused Scherer’s injuries. The issue whether the evidence was sufficient to establish that Scherer’s injuries were “serious” was preserved for appellate review by a timely objection at trial, and by the defendant’s motion for a required *118finding of not guilty. We thus review the denial of this aspect of the defendant’s motion under the standard set forth in Commonwealth v. Latimore, supra at 677-678. The issue of the sufficiency of the evidence of causation was not preserved. We review this unpreserved error under the substantial risk of a miscarriage of justice standard. See Commonwealth v. Melton, 436 Mass. 291, 294 n.2 (2002).
In reviewing the sufficiency of the evidence, we must look at the evidence in a light most favorable to the Commonwealth to determine whether any rational jury could have found the essential elements beyond a reasonable doubt. Commonwealth v. Latimore, supra at 676-677. The Commonwealth need only present evidence that allows a jury to infer essential facts, Commonwealth v. Merola, 405 Mass. 529, 533 (1989), and the fact “[tjhat contradictory evidence exists is not a sufficient basis for granting a motion for a required finding of not guilty.” Commonwealth v. Merry, 453 Mass. 653, 662 (2009). As the defendant had two reasons for contesting the denial of the motion for a required finding, we take each in turn.
a. Serious bodily injury. “[Sjerious bodily injury” is defined as “bodily injury that results in a permanent disfigurement, loss or impairment of a bodily function, limb or organ, or a substantial risk of death.” G. L. c. 265, § 13A (c). Loss or impairment of a bodily function need not be permanent to meet the definition of “serious bodily injury.” See Commonwealth v. Baro, 73 Mass. App. Ct. 218, 219-220 (2008) (punches and kicks to head resulting in broken bones and temporary loss of sight for one and one-half months constitutes “serious bodily injury”); Commonwealth v. Jean-Pierre, 65 Mass. App. Ct. 162, 162, 164 (2005) (punches resulting in broken jaw and several weeks of tube-feeding constitutes “serious bodily injury”).
The defendant argues that there was insufficient evidence that Scherer suffered loss or impairment of a bodily function, limb, or organ. He relies on the hospital records and claims that they offer no evidence of impairment to Scherer’s vision. The defendant paints an incomplete picture of the evidence of Scherer’s significant vision loss following the violent confrontation with the defendant. Although some of the medical records do not reflect that Scherer’s vision was impaired, other records state *119that Scherer presented with “blurred vision” and “vision changes.” Scherer also testified to his impaired vision following the fight with Parietti and the defendant. He testified that he had to return to the hospital multiple times after undergoing facial reconstruction surgery to ensure that his vision kept improving. He stated that he experienced double vision for three or four months following the altercation and that he still was having trouble seeing at the time of trial, which was more than one year after the fight. This testimonial evidence of significant and lasting vision impairment, even if it conflicts with some of the medical records, indicates that Scherer’s injuries were not — as the defendant suggests — mere “facial injuries resulting from a fistfight.” To the contrary, the evidence was such that a reasonable jury could have found “serious bodily injury” within the meaning of G. L. c. 265, § 13A (b) (z).
b. Whether the defendant caused Scherer’s injuries. The defendant also asserts that the judge erred in denying his motion for a required finding of not guilty because there was insufficient evidence to establish that the defendant’s and not Parietti’s actions caused Scherer’s injuries. He suggests that the combination of the defendant’s acquittal of assault and battery with a dangerous weapon and the fact that the defendant entered the fight after Parietti is such that no reasonable jury could have found the essential causation element.
At the close of all the evidence, the Commonwealth requested and the judge denied a joint venture jury instruction. Therefore, the burden was on the Commonwealth to prove causation beyond a reasonable doubt as to the defendant. Because the defendant did not preserve the causation issue, we review the denial of the motion to determine whether any error resulted in a substantial miscarriage of justice. Commonwealth v. Melton, supra. We conclude that there was none.
The Commonwealth may establish causation in an assault and battery case by proving beyond a reasonable doubt that the defendant either directly caused or “directly and substantially set in motion a chain of events that produced” the serious injury in a natural and continuous sequence. See Instruction 6.160 of the Criminal Model Jury Instructions for Use in the District Court (2009). Cf. Commonwealth v. Smiley, 431 Mass. 477, 489 *120n.9 (2000). The judge correctly instructed the jury on these methods of proving causation. Although the evidence of who did what to whom was conflicted, it did not thereby become insufficient. The jury could have found that the defendant caused serious injury (fractured orbital bones and double vision) to Scherer by kicking Scherer in the head while Scherer was holding Parietti on the ground, thereby rendering Scherer unconscious. The fact that the defendant was acquitted on the assault and battery with a dangerous weapon charge4 does not disprove that there was direct contact attributable solely to the defendant.5 Because there was sufficient evidence to support the jury’s verdict, we conclude there was no error in the denial of the motion for a required finding of not guilty.
3. Motion to dismiss based on the loss of exculpatory evidence. The defendant asserts error in the denial of his motion to dismiss the complaint where the Commonwealth allegedly lost potentially exculpatory evidence, namely, a statement Scherer reportedly wrote following the altercation with Parietti and the defendant. The issue was preserved at trial. The basis for the motion was the testimony of a police officer who arrived on the scene following the altercation. He recalled reading Scherer’s statement but was unsure what had become of it. He did not know whether Scherer had ever given the statement to the police or if the police had misplaced it. It was the defendant’s position that any *121discrepancies between the statement and Scherer’s testimony would have undercut Scherer’s credibility as a witness; therefore, the defendant claims, he was deprived of a meaningful opportunity for cross-examination by the Commonwealth’s failure to produce the statement.
To state a claim that the government has lost or destroyed potentially exculpatory evidence, the defendant has the burden of establishing, based on concrete evidence, that there was a reasonable possibility that the allegedly lost statement would have supported his case. See Commonwealth v. Williams, 455 Mass. 706, 718 (2010). The trial judge then must “weigh the materiality of the evidence and the potential prejudice to the defendant, as well as the culpability of the Commonwealth and its agents.” Commonwealth v. Harwood, 432 Mass. 290, 295 (2000). We, in turn, review the judge’s determination for clear error. See id.
We conclude that the judge did not err in denying the motion to dismiss. The defendant presented no evidence whatsoever of the contents of the elusive statement. His claim that it would have been inconsistent, much less materially inconsistent, is speculative. Therefore, he did not meet his threshold burden of proving that the statement was exculpatory.6
4. Failure to instruct the jury on multiple defendants. The judge denied the Commonwealth’s request to instruct the jury on joint venture.7 The defendant alleges error in the judge’s failure to use the model jury instruction applicable to cases with multiple defendants, and to his use of the singular “defendant” as opposed to the plural “defendants” in instructing the jury. The consequence, according to the defendant, was avoidable jury confusion as to which of the two defendants was responsible for each distinct act.
*122We evaluate jury instructions as a whole and interpret them as would a reasonable juror. Commonwealth v. Trapp, 423 Mass. 356, 361, cert, denied, 519 U.S. 1045 (1996). We do not require that judges use particular words, but only that legal concepts are properly conveyed. Id. at 359. Because the defendant did not object to the jury instruction at trial, we review his claim to determine first whether there was error, and if so, we then inquire whether the error created a substantial risk of a miscarriage of justice. See Commonwealth v. Belcher, 446 Mass. 693, 696 (2006).
The defendant’s argument is unpersuasive. In his instructions, the judge emphasized that each defendant faced distinct charges and differentiated between the charges against each individual defendant. Significantly, he instructed the jury that the “burden of the Commonwealth is to prove every single element of the charge against each defendant beyond a reasonable doubt.” In so doing, the judge correctly conveyed the law. Because there was no error of law, there was no substantial miscarriage of justice.8 See Commonwealth v. Randolph, 438 Mass. 290, 303 (2002).
5. Denial of the motion for a new trial. The defendant moved, pursuant to Mass. R. Crim. R 30 (b), as appearing in 435 Mass. 1501 (2001), for a new trial on the ground that he was deprived of his right to the effective assistance of counsel under the Sixth Amendment to the United States Constitution and art. 12 of the Massachusetts Declaration of Rights. His counsel’s alleged failings were many,9 and they occurred at different stages of the litigation. Counsel’s purported deficiencies included the failure (1) to advise the defendant prior to trial of the potential immigration consequences of an assault and battery conviction at trial, (2) to discuss the possibility of a plea resolution with the *123defendant, and (3) to advocate for a sentence that might have mitigated the immigration consequences of a conviction.
A hearing on the motion was held in June, 2012, after which the motion was denied. We review the denial of the motion for abuse of discretion. See Commonwealth v. Lucien, 440 Mass. 658, 670 (2004). A defendant bears the burden of proof on a motion for a new trial,10 see Commonwealth v. Watson, 455 Mass. 246, 256 (2009), and a judge is entitled to discredit affidavits he or she does not find credible, see Commonwealth v. Grace, 370 Mass. 746, 751-752 (1976), citing Commonwealth v. Heffernan, 350 Mass. 48, 53, cert, denied, 384 U.S. 960 (1966). We conclude that the judge did not abuse his discretion and affirm the order denying the motion for a new trial. We reach this conclusion because the defendant offered no proof that there was “a ‘reasonable probability’ that ‘but for counsel’s unprofessional errors, the result of the proceeding would have been different.’ ” Commonwealth v. Mahar, 442 Mass. 11, 15 (2004), quoting Strickland v. Washington, 466 U.S. 668, 694 (1984). See Missouri v. Frye, 132 S. Ct. 1399, 1410 (2012) (Frye); Lafler v. Cooper, 132 S. Ct. 1376, 1385 (2012) (Lafler).
The two-part test a defendant must satisfy to prevail on a claim of ineffective assistance of counsel in Massachusetts is familiar. The defendant must show that counsel’s performance fell “measurably below that which might be expected from an ordinary fallible lawyer,” and that his performance “likely deprived the defendant of an otherwise available, substantial ground of defence.”11 Commonwealth v. Saferian, 366 Mass. 89, 96 (1974) (Saferian). Although the defendant’s claim fails for lack of proof of prejudice, we consider whether defense *124counsel’s performance fell “measurably below that which might be expected from an ordinary fallible lawyer,” id., before we address the prejudice issue.
a. Professional standards. We consider defense counsel’s performance under the first prong of Saferian in light of Padilla v. Kentucky, 130 S. Ct. 1473 (2010) (Padilla), a recent case in which the United States Supreme Court held that counsel must advise a defendant that a guilty plea may carry deportation consequences. In Padilla, supra at 1480, the Court chronicled the changes in immigration law that have led to an increase in deportable offenses and concluded that “deportation is an integral part — indeed, sometimes the most important part” — of the criminal process. Because of this intimate connection between the criminal process and deportation, the Court declined to regard deportation as a mere “collateral consequence” of criminal conviction. Underlying the Supreme Court’s decision that deportation consequences are not “collateral” to the criminal justice process and thus not removed from a noncitizens’ Sixth Amendment right to counsel is a deep appreciation of the “seriousness of deportation” for noncitizen defendants. Id. at 1486. Indeed, “[preserving the client’s right to remain in the United States may be more important to the client than any potential jail sentence.” Id. at 1483, quoting Immigration & Naturalization Serv. v. St. Cyr, 533 U.S. 289, 323 (2001). With the changed landscape following Padilla in mind, we briefly address each of counsel’s alleged failings individually.
i. Failure to advise defendant of immigration consequences of conviction at trial. An initial issue in this appeal is whether the Supreme Court’s holding in Padilla, supra at 1486, that defense counsel must advise noncitizen clients that pleading guilty may result in deportation, requires counsel to inform a noncitizen client that conviction at trial may similarly carry immigration consequences. We hold that it does. Although Padilla and its progeny, Frye, supra, and Lafler, supra, concerned the duties of counsel in the plea context, the language of Padilla, much of which this court acknowledged in Commonwealth v. Clarke, 460 Mass. 30, 42-46 (2011) (Clarke), implicates counsel’s duties in the context of advice rendered to clients about immigration consequences more broadly. For example, the Court states *125that counsel has an affirmative duty12 to “advise a noncitizen client that pending criminal charges may carry a risk of adverse immigration consequences. ”13 Padilla, supra at 1483. See Clarke, supra at 42. Such broad language suggests that Padilla imposes on defense counsel a duty to inform a noncitizen client that conviction, whether by plea or by trial, may carry adverse immigration consequences.14 Padilla, supra at 1482-1483. Clarke, supra. Moreover, national guidelines15 dictate “that counsel must advise her client regarding the risk of deportation,” without specific reference to conviction by guilty plea. Padilla, supra at 1482, citing National Legal Aid & Defender Ass’n, Performanee Guidelines for Criminal Representation § 6.2 (1995). See J.W. Hall, Jr., Professional Responsibility in Criminal Defense Practice § 10:29 (3d ed. 2005) (“The failure to advise a defendant that he could be deported if convicted . . . would constitute ineffectiveness”). Similarly, the expectation in the Massachusetts legal community is that defense counsel should inform a client about immigration consequences associated with criminal conviction, however imposed. See Committee for Public Counsel Services, Assigned Counsel Manual c. 4, at 15 (rev. June 2011) (CPCS Manual) (“Counsel must also advise the client ... of the consequences of a conviction, including . . . possible immigration consequences including but not limited to deporta*126tion, denial of naturalization or refusal of reentry into the United States”).16 Because “[i]t is quintessentially the duty of counsel to provide her client with available advice about an issue like deportation,” Clarke, supra at 46, quoting Padilla, supra at 1484, and the defense counsel in the present case failed to do so, we conclude that his performance fell “measurably below that which might be expected from an ordinary fallible lawyer.” See Saferian, supra.
ii. Failure to discuss plea resolution with defendant.17 Padilla is not directly applicable outside the context of defense counsel’s duty to advise a noncitizen client that immigration consequences may flow from conviction, whether by plea or by trial. Immigration consequences may nevertheless factor into litigation strategy, including at plea and sentencing stages. That immigration consequences inform trial strategy is appropriate given the grave impact involvement with the criminal justice system can have on a noncitizen defendant’s immigration status and the view, following Padilla, that immigration consequences like *127deportation are no longer collateral to conviction. With these ideas in mind, we turn to the defendant’s two other claims of at-tomey error: that defense counsel failed to discuss the possibility of a plea resolution and to advocate for a sentence that might have mitigated the immigration consequences of a conviction. We “judge the reasonableness of counsel’s challenged conduct on the facts of the particular case,” Clarke, supra at 38, quoting Strickland v. Washington, 466 U.S. 668, 690 (1984), and “decline[] to define the constitutional obligations of counsel in more specific terms.” Clarke, supra. See Roe v. Flores-Ortega, 528 U.S. 470, 479-480 (2000) (rejecting bright-line rules governing constitutional duties of counsel).
It is undisputed that a criminal defendant has no constitutional right to a plea bargain. Lafler, supra at 1395. Moreover, the prosecutor in the present case never put a formal plea offer on the table. Cf. Frye, supra at 1408-1409. Nevertheless, defense counsel should have informed the defendant that the prosecution was interested in discussing a plea resolution and proceeded to discuss that possibility with the defendant prior to trial. Today, “[pjleas account for nearly 95 [per cent] of all criminal convictions.” Padilla, supra at 1485. It is standard practice that “the attorney should explore all alternatives to trial, including the possible resolution of the case through a negotiated plea or admission to sufficient facts.” CPCS Manual, supra at c. 4, at 46. In the present case, defense counsel knew that the defendant faced possible deportation and yet failed to tell the defendant that the prosecutor twice approached him about the possibility of plea resolution. Thus, whether a plea was a real option or would have resulted in less severe immigration consequences, the defendant was deprived of the opportunity to make an intelligent decision, based on greater information, about whether to proceed to trial or to request that counsel engage in plea negotiations. See Frye, supra; Mass. R. Prof. C. 1.2, 426 Mass. 1310 (1998) (client’s decision to accept plea); Mass. R. Prof. C. 1.4, 426 Mass. 1314 (1998) (client communication). For these reasons, counsel’s performance was deficient.
iii. Failure to advocate for lesser sentence. We similarly conclude that counsel’s failure to argue for a shorter sentence *128fell measurably below requisite professional standards.18 In Padilla, supra at 1486, the Supreme Court emphasized that criminal conviction may carry severe immigration consequences for a noncitizen criminal defendant and his family. We likewise appreciate the grave impact sentencing can have on deportability. For a noncitizen defendant, the difference between imposed sentences of 364 days and of one year following convictions of simple assault or aggravated assault and battery may be the difference between life in this country and deportation. See D. Kesselbrenner & W. Wayne, Defending Immigrants Partnership, Selected Immigration Consequences of Certain Massachusetts Offenses 3, 4 (2006) (Kesselbrenner & Wayne). Moreover, the standard practice for defense counsel in Massachusetts is to consider the immigration consequences that may attach to a sentence and to “zealously advocate the best possible disposition” for the client.19 CPCS Manual, supra at c. 4, at 22-24. In failing to do so, counsel’s performance fell “measurably below that which might be expected from an ordinary fallible lawyer.” Saferian, supra.
b. Prejudice. Having determined that counsel’s performance failed to satisfy the first prong of Saferian, supra, we now reach the central reason for the disposition of this appeal: the defendant’s failure to show that he was prejudiced by counsel’s performance. We conclude that the defendant is not entitled to a new trial because he offers no proof of prejudice. In support of his argument that he was prejudiced by counsel’s allegedly deficient performance, the defendant relies on his own affidavit, *129as well as affidavits from his counsel, the codefendant’s counsel, and the assistant district attorney. These affidavits merely reflect counsel’s purported failures and do not establish that “better work might have accomplished something material for the defense.” Commonwealth v. Dargon, 457 Mass. 387, 403 (2010), quoting Commonwealth v. Satterfield, 373 Mass. 109, 115 (1977).
i. Failure to advise defendant of immigration consequences of conviction. The defendant argues that, had he known the potential immigration consequences of the charges, he would have requested that counsel engage in plea negotiations in an attempt to lessen the immigration consequences. He shows no specific prejudice from counsel’s failure to inform him of the consequences of conviction at trial but, instead, relies on the other two areas of ineffectiveness to establish over-all prejudice.
ii. Failure to discuss possibility of plea resolution with defendant. To establish prejudice on account of counsel’s deficient performance in the plea context, the defendant must show a reasonable probability that the result of a plea would have been more favorable than the outcome of the trial. See Frye, supra at 1409; Lafler, supra at 1385. In particular, the defendant must demonstrate a reasonable probability that the prosecution would have made an offer, that the defendant would have accepted it, and that the court would have approved it. See Frye, supra (concluding that defendant had not established prejudice because of “strong reason to doubt the prosecution and the trial court would have permitted the plea bargain to become final”); Lafler, supra (“defendant must show that but for the ineffective advice of counsel there is a reasonable probability that the plea offer would have been presented to the court . . ., that the court would have accepted its terms, and that the conviction or sentence, or both, under the offer’s terms would have been less severe than under the judgment and sentence that in fact were imposed”).20 Moreover, “[pjroof of prejudice . . . cannot be based on mere conjecture or speculation as to outcome.” People *130v. Palmer, 162 Ill. 2d 465, 481 (1994), cert, denied, 514 U.S. 1086 (1995).
The affidavits submitted by the defendant merely state that defense counsel decided against engaging in a plea negotiation or discussing that option with the defendant. The defendant offered no evidence that the prosecutor would have offered him a favorable plea bargain, or that the judge would have accepted one. Evidence that there was no plea negotiation also does not establish that there was any real opportunity to avoid the immigration consequences of a conviction, particularly for an undocumented person. The reality of the defendant’s status as an undocumented person living in the United States was that he was deportable per se on account of his unlawful status.21 The *131defendant was, in fact, removed from this country following his criminal proceedings. Although plausible, we have been shown no evidence that the defendant’s criminal activity made him a more likely target for deportation. The defendant provided no proof that his counsel’s conduct as opposed to his undocumented status led to his deportation. See, e.g., United States vs. Martinez, U.S. Dist. Ct., Nos. 07-91(5), 10-2553, slip op. at 4 (D. Minn. Dec. 17, 2010) (finding no prejudice because guilty plea had no bearing on defendant’s deportability given his undocumented status).
The defendant contends that, had the Commonwealth agreed to a disposition by a plea to simple assault, he would have avoided deportation. This argument also fails for lack of proof. We have been shown no evidence22 that criminal convictions carry the same deportation consequences for undocumented immigrants as they do for lawful immigrants.23 The only evidence included in the record is a chart that, even if it were equally as applicable to undocumented immigrants as it is to lawful immigrants, does not advance the defendant’s position. The chart indicates that simple assault, like assault and battery causing serious bodily injury, may result in deportation of a noncitizen defendant if the sentence imposed is one year or more. 8 U.S.C. § 1227 (2006 & Supp. II) (aggravated felonies are deportable offenses).24 See Kesselbrenner & Wayne, supra at 3,4. Therefore, even if the prosecutor had offered a plea to simple assault — *132and there is no evidence that he might have — the defendant well may have faced the same immigration consequence as he did following conviction of assault and battery causing serious bodily injury.
iii. Failure to advocate for lesser sentence. We know that a jury convicted the defendant of assault and battery causing serious bodily injury and, therefore, that the judge imposed a sentence based on this conviction. We also know that the defendant was sentenced to two and one-half years in a house of correction, and was required to serve nine months with the balance suspended.25 We are told by the defendant and his counsel in the form of affidavits that defense counsel did not raise the immigration consequences with the judge for consideration in sentencing. Even taking the affiants at their word, something we are not required to do, we are disturbed by the dearth of proof of counsel’s performance at sentencing. The defendant failed to provide a transcript of the sentencing hearing. See Commonwealth v. Watson, 455 Mass. 246, 256 (2009). If a transcript was unavailable, the defendant also failed to avail himself of the opportunity afforded in our Rules of Appellate Procedure to file a statement of the evidence. Mass. R. A. P. 8 (c), as amended, 378 Mass. 932 (1979). Consequently, we do not know what factors the judge considered in fashioning the sentence or whether he would have imposed a lighter sentence had the potential immigration consequences been argued to him.26
Moreover, we have been shown no evidence that a lighter sentence might have allowed the undocumented defendant to “fly under the radar” and avoid deportation. Even assuming criminal convictions carry the same deportation consequences for undocumented immigrants as they do for lawful immigrants, we have no evidence that deportation would not have been the *133consequence of the aggravated assault and battery conviction, irrespective of the length of the sentence. See 8 U.S.C. § 1227(a)(2)(A)(i). See also Kesselbrenner & Wayne, supra at 4 (aggravated assault and battery may qualify as “crime involving moral turpitude” rendering defendants deportable regardless of sentence length).27 Thus, because the undocumented defendant offered no evidence that his fate would have been different if defense counsel had argued for a lighter sentence, we cannot conclude that he was prejudiced.
Judgment affirmed.
Order denying motion for a new trial affirmed.
The alleged dangerous weapon was a boot or a “shod foot.”
We acknowledge the amicus brief of the Committee for Public Counsel Services.
Although Cardinal also was involved in the altercation and suffered injuries, her involvement is not relevant to this appeal. Carwile’s involvement is also immaterial.
Because an issue at trial was the type of footwear the defendant was wearing, the jury could have acquitted him on the ground that the footwear did not constitute a deadly weapon.
In the alternative, the jury could have found that the concurrent actions of Parietti and the defendant, both of whom landed blows on Scherer within a short period of time, caused Scherer’s severe injuries. See Commonwealth v. Perry, 432 Mass. 214, 225-226, 229 (2000) (deciding that, although cumulative effect of multiple beatings caused victim’s death, evidence was sufficient for jury to conclude that defendant caused victim’s death on theory of individual liability); Commonwealth v. McLeod, 394 Mass. 727, 745, cert, denied sub nom. Aiello v. Massachusetts, 474 U.S. 919 (1985) (where there is more than one proximate cause, “liability ... [is not required to] be related to any theory of joint liability”). In yet another alternative, although the judge did not instruct the jury on joint venture, joint venture was a viable theory at the time the Commonwealth rested; therefore, evidence supporting conviction on joint venture theory could be considered in determining the sufficiency of the evidence of causation. See Commonwealth v. Mills, 436 Mass. 387, 393 (2002).
Contrary to the defendant’s argument, the judge did not usurp the jury’s fact-finding prerogative in merely reflecting that he was “not so sure [the statement] did exist” when the police officer had testified the previous day that he read the report. The judge was not addressing the jury at the time and, thus, could not have invaded the jury’s function. See Commonwealth v. McCall, 375 Mass. 316, 321 (1978). In addition, the judge did not remove from the jury’s consideration any factual issues that the defendant was entitled to have the jury resolve.
Counsel for Parietti, the codefendant, objected to the Commonwealth’s request for a joint venture instmction. Counsel for the defendant did not.
The defendant makes an additional argument that his defense counsel was ineffective in failing to request a jury instruction on how to evaluate a case with multiple defendants. Because there was no error of law giving rise to a substantial miscarriage of justice, there could not have been ineffective assistance of counsel. See Commonwealth v. Emeny, 463 Mass. 138, 153 (2012); Commonwealth v. Wright, 411 Mass. 678, 682 (1992).
In addition to the claims we discuss at greater length, the defendant also alleges that his counsel failed to prepare him to testify at trial and to inform him of the elements of the charged offenses and relevant defenses. The trial transcript does not indicate lack of preparedness.
The defendant and his trial attorney, who was not appellate counsel, submitted affidavits that attest to the defendant’s claims. The codefendant’s attorney and the assistant district attorney also submitted affidavits that indicate that the defendant’s trial counsel would not engage in a plea negotiation.
Satisfying Commonwealth v. Saferian, 366 Mass. 89, 96 (1974) (Saferian), necessarily satisfies the Federal standard articulated in Strickland v. Washington, 466 U.S. 668, 694 (1984), for evaluating the constitutional effectiveness of counsel. Commonwealth v. Clarke, 460 Mass. 30, 45 (2011) (Clarke). In fact, we “grant more expansive protections under [art. 12 of the Massachusetts Declaration of Rights] than have been required of States under the Sixth Amendment.” Commonwealth v. Rainwater, 425 Mass. 540, 553 (1997), cert, denied, 522 U.S. 1095 (1998).
Padilla v. Kentucky, 130 S. Ct. 1473, 1484 (2012) (Padilla), makes plain that defense counsel has an affirmative duty to advise a noncitizen criminal client about the immigration consequences of involvement in the criminal justice system; a defense counsel who remains silent about potential immigration consequences fails to provide constitutionally effective counsel. See Clarke, supra at 43.
In Padilla, supra at 1483, the precise immigration consequences of the noncitizen defendant’s conviction of transporting marijuana were “succinct, clear, and explicit” and easily ascertainable “simply from reading the text of the statute.” See 8 U.S.C. § 1227(a)(2)(B)(i) (2006). Therefore, the Court determined that defense counsel should have advised his client that conviction would result in deportation. The substantive adequacy of counsel’s advice is not at issue in this case because the record indicates that defense counsel said nothing to the defendant about the immigration consequences of conviction.
In the aftermath of Padilla, earlier characterizations of immigration consequences as “collateral” are no longer good law. See, e.g., United States v. Fry, 322 F.3d 1198, 1200 (9th Cir. 2003), and cases cited,
Constitutional deficiency is “necessarily linked to the practice and expectations of the legal community.” Clarke, supra at 42, quoting Padilla, supra at 1482.
Although we are not bound by the Committee for Public Counsel Services’s Assigned Counsel Manual (rev. June 2011) (CPCS Manual), we find it persuasive. We further note that the CPCS Manual governs the conduct of both assigned and appointed counsel. CPCS Manual, supra at c. 1, at 1.
In his brief, the defendant often frames this allegation as counsel’s failure to engage in plea negotiations with the prosecutor. We agree with the defendant that it is generally prudent practice for defense counsel to explore the possibility of a plea bargain, particularly in light of potentially severe immigration consequences of conviction. See, e.g., CPCS Manual, supra at c. 4, at 46. However, defense counsel does not have an absolute duty to engage in plea negotiations. See American Bar Association, Standards for Criminal Justice, Prosecution Function and Defense Function § 4-6.2, at 205 (3d ed. 1993) (“Plea discussions should be considered the norm and failure to seek such discussions is an exception unless defense counsel concludes that sound reasons exist for not doing so” [emphasis added]); G.N. Herman, Plea Bargaining § 3:03, at 21 (3d ed. 2012) (“for purposes of effective assistance of counsel, a defense attorney has no duty to enter into plea negotiations . . .”). Claims of ineffective assistance of counsel for failure to engage in plea negotiations have typically been rejected when defense counsel has a justifiable explanation for making the strategic decision not to explore a plea deal. See, e.g., People v. Sherman, 172 P.3d 911, 913 (Colo. Ct. App. 2006); People v. Palmer, 162 Ill. 2d 465, 478-479 (1994), cert, denied, 514 U.S. 1086 (1995). See also D. Kesselbrenner & W. Wayne, Defending Immigrants Partnership, Selected Immigration Consequences of Certain Massachusetts Offenses 3 (2006); Annot., Adequacy of Defense Counsel’s Representation of Criminal Client Regarding Plea Bargaining, 8 A.L.R.4th 660, at § 2(a) (1981).
As we discuss later, we are disturbed by the dearth of proof of counsel’s performance at sentencing.
Reasoning that immigration consequences are collateral to conviction, this court has held that a trial judge should not consider the potential immigration consequences in fashioning a sentence. See Commonwealth v. Quispe, 433 Mass. 508, 513 (2001). This reasoning was undermined in Padilla when the Supreme Court declined to accept the view that immigration consequences are collateral to conviction. Padilla, supra at 1481. Therefore, our precedent that a trial judge cannot factor immigration consequences into sentencing is no longer good law. See Commonwealth v. Quispe, supra at 512-513. See, e.g., United States v. Kwan, 407 F.3d 1005, 1017 (9th Cir. 2005) (judge may factor immigration consequences into sentencing); United States v. Castro, 26 F.3d 557, 560 (5th Cir. 1994) (same). See also, e.g., Note, Extracting Compassion from Confusion: Sentencing Noncitizens after United States v. Booker, 79 Fordham L. Rev. 2129, 2156-2165 (2011).
The dissent contends that the defendant was altogether denied the assistance of counsel at a critical plea negotiation stage of the proceedings. This, according to the dissent, is per se ineffective assistance of counsel for which no specific showing of prejudice is required. Post at 137-138, 144. The basis
*130for this outcome is Roe v. Flores-Ortega, 528 U.S. 470, 483-484 (2000) (Flores-Ortega), a case involving counsel’s failure to file a notice of appeal that resulted in the forfeiture, effectively a complete denial, of a judicial proceeding altogether.
The dissent’s reliance on Flores-Ortega is misplaced. Although the right may be waived, see Commonwealth v. Petetabella, 459 Mass. 177, 181 (2011), criminal defendants in Massachusetts have a statutory right of appeal. G. L. c. 278, § 28. See Commonwealth v. Cowie, 404 Mass. 119, 122 (1989). Criminal defendants have no right to a plea bargain. Lafler v. Cooper, 132 S. Ct. 1376, 1395 (2012) (Lafler). Therefore, counsel’s failure to discuss the possibility of a plea bargain did not deprive the defendant of any rights. Said differently, the defendant forfeited nothing. Moreover, in relying on Flores-Ortega, the dissent completely disregards the fact that both the Supreme Court and this court have required a showing of actual prejudice in analogous contexts. See Missouri v. Frye, 132 S. Ct. 1399, 1409 (2012) (lapsed plea); Lafler, supra at 1385 (rejected plea); Clarke, supra at 47-49 (uninformed guilty plea). See also Padilla, supra at 1487 (remanding for proceedings on actual prejudice). Courts in other jurisdictions that have considered the evidence necessary to satisfy the prejudice prong of an ineffective assistance claim in the context of counsel’s failure to adequately explore a plea resolution similarly required a showing of actual prejudice. See, e.g., United States v. Boone, 62 F.3d 323, 327 (10th Cir.), cert, denied, 516 U.S. 1014 (1995) (no proof that plea would have been acceptable to judge or that resulting sentence would have been different); People v. Sherman, 172 P.3d 911, 914 (Colo. App. 2006) (no proof of defendant’s willingness to accept plea offer); People v. Palmer, 162 Ill. 2d 465, 481 (1994) (no proof that State would have offered plea deal).
Our consideration of the defendant’s undocumented status in no way implies that an undocumented defendant can never successfully state a claim of ineffective assistance of counsel. New avenues may open in the ever-changing field of immigration law that change the legal landscape for undocumented people. We simply ask that undocumented defendants address the issue of their particular status and how different performance of counsel could have led to a better outcome.
Appellate counsel structured the appeal based on the assumption that the undocumented defendant’s conviction led to his deportation, and the record, although unclear, suggests that trial counsel acted under a similar assumption. We are under no obligation to accept this unsupported assumption.
The grounds of deportability under Federal statute presuppose that an immigrant was lawfully “admitted.” 8 U.S.C. § 1101(a)(13)(A) (2006) (defining “admission” as lawful entry into United States). 8 U.S.C. § 1227(a)(2)(A)(iii) (“Any alien who is convicted of an aggravated felony at any time after admission is deportable”). The defendant in this case was not admitted lawfully; he was in this country illegally.
The reason that simple assault and aggravated assault and battery convictions that carry an imposed sentence of one year or more may render a lawful immigrant deportable is that both offenses may constitute “aggravated felon[ies],” defined as “crim[es] of violence,” 8 U.S.C. § 1101(a)(43)(F) (2006), or “offense[s] that [have] as an element the use, attempted use, or threatened use of physical force against the person or property of another.” 18 U.S.C. § 16 (2006). The alternative elements of simple assault in Massachusetts *132— the attempted or threatened use of physical force against the person of another, see Commonwealth v. Gorassi, 432 Mass. 244, 248 (2000) — mirror the definition of “crime[s] of violence” under Federal statute.
A sentence remains a sentence for immigration purposes, even if its imposition or execution has been suspended in whole or in part. See 8 U.S.C. § 1101(a)(48)(B) (2006).
That the sentencing judge only required the defendant to serve, nine months of his sentence does not necessarily indicate a willingness to impose a lighter sentence, even if potential immigration consequences were brought to his attention.
Irrespective of his conviction, the defendant is subject to a term of inadmissibility because he was removed following a period of unlawful presence in this country. 8 U.S.C. § 1182(a)(9) (2006) (inadmissibility of aliens previously removed). Because his sentence was for over one year, and thus his aggravated assault and battery conviction amounted to an “aggravated felony,” he may be inadmissible for longer. Id. There is also the possibility that he will never be able to return. Id. Because we were provided no information about these issues, we cannot conclude that a remand for resentencing would serve the defendant’s interests.