The defendant, Thomas A. Woods, appeals from the denial of his motion for a new trial. In 2009, the defendant was convicted of murder in the first degree and sentenced to life in prison. On direct appeal, he challenged the admission of his grand jury testimony -- later used as substantive evidence at trial -- arguing that it was illegally obtained, because he was not informed before testifying either that he was a target of a grand jury investigation, or that he had a right against self-incrimination. The court concluded that the trial judge did not err in finding that the defendant was not a target of the grand jury when he was called before the grand jury to testify, and affirmed his conviction. See Commonwealth v. Woods, 466 Mass. 707, 709, 716-720, 1 N.E.3d 762, cert. denied, --- U.S. ----, 134 S.Ct. 2855, 189 L.Ed.2d 818 (2014) ( Woods I ). In doing so, the court also announced a prospective rule, pursuant to its superintendence authority, requiring that grand jury witnesses who are targets or likely targets of a criminal investigation be given self-incrimination warnings before testifying. Id. at 719-720, 1 N.E.3d 762.
Following Woods I, the defendant moved for a new trial, contending that facts not before the trial judge or this court during his direct appeal establish that the defendant was a target of a grand jury investigation; accordingly, the defendant argued, his grand jury testimony was improperly admitted, and he deserved a new trial. The motion judge, who was not the trial judge, disagreed, concluding that although the new facts raised in the defendant's motion establish that he was a target of the investigation, this court's holding in Woods I"was not dependent on the finding that the defendant was not a target." The defendant then filed a petition before a single justice of the county court pursuant to G. L. c. 278, § 33E, asking that his appeal from the denial of his motion be considered by the full court. The single justice granted the petition in March, 2017, concluding that it "present[ed] a new and substantial question which ought to be determined by the full court." G. L. c. 278, § 33E.
For the reasons that follow, we discern no error in the motion judge's conclusion, *963and affirm the denial of the defendant's motion for a new trial.
Background. The facts underlying the defendant's conviction of murder in the first degree are fully set forth in Woods I, 466 Mass. at 709-712, 1 N.E.3d 762. We review only those facts pertinent to the defendant's postconviction proceedings.
1. Grand jury investigation. In February, 2006, the defendant appeared as the fifth witness to testify before a grand jury investigating the December, 2005, shooting death of Paul Mullen in Brockton. Prior to testifying, the defendant had been interviewed by police twice. Four witnesses testified before the grand jury prior to the defendant, and two of those witnesses -- David Sheff and Nicole Derochea -- stated that they had had heard, secondhand, that the defendant had threatened to shoot the victim before the killing occurred. When the defendant appeared to testify, he was not informed that he was a target of the investigation or that he had a right against self-incrimination. In his grand jury testimony, he provided an exculpatory version of events on the night of the shooting, and explained certain inconsistencies between this version of events and what he had said during his prior interviews with police. At the end of a nine-month investigation that involved approximately forty witnesses and generated 1,700 pages of transcripts, the grand jury returned an indictment against the defendant in October, 2006.
2. Defendant's pretrial motion in limine. In March, 2009, the defendant filed a motion in limine to exclude his grand jury testimony from use at his trial,1 arguing that he was "not informed that [he] was a target of the grand jury investigation" or that he could exercise his right not to testify. The motion stated the date of the defendant's grand jury appearance (February 10, 2006). The Commonwealth sought to introduce that testimony in order to illustrate "wide-ranging inconsistencies and implausibilities in [the defendant's] account[ ]" of the night of the shooting. See Woods I, 466 Mass. at 712, 1 N.E.3d 762 ("His grand jury testimony was admitted in evidence ... to illustrate his conflicting stories and outright lies").
3. Commonwealth's pretrial motion in limine. On April 24, 2009, the Commonwealth filed its own motion in limine seeking to admit evidence of prior bad acts by the defendant. The motion described the testimony of five grand jury witnesses, including Derochea, who were expected to testify at trial regarding threats made by the defendant against the victim. The Commonwealth attached to the motion the transcripts of the five witnesses' testimony. It is not clear from the record, however, the form in which those transcripts were presented -- specifically, whether the attachments clarified the date of each witness's testimony -- because those attachments were not included with the Commonwealth's motion as part of the instant record.2
4. Pretrial hearing on the motions. On April 27, 2009, the trial judge held a hearing on both motions. Defense counsel reiterated the position that the defendant's testimony was involuntary because he was a target of the investigation but did not receive "any warnings that he didn't have to submit to that questioning or that he could assert his Fifth Amendment privilege."
*9643 He argued that the issue was "whether or not the government was under any obligation to inform [the defendant] he was the target of the investigation and ... that he had a Fifth Amendment privilege." Counsel acknowledged that he "ha[d]n't found a state case directly on point," and stated that his argument was based on his own practical experience, having never witnessed a situation where a grand jury target was not informed of that status or given warnings before testifying. Before asking the Commonwealth for its position, the trial judge likewise stated, "I didn't realize this was an issue, so I haven't researched the law on it. I know in the federal system if somebody's going to be a target, they're told. But I haven't researched this whole issue, but I will."
The trial judge asked the prosecutor, who had also been responsible for the grand jury investigation: "At the time -- if you can say this, because it would change the whole way that I'd have to view this, in your opinion, was [the defendant] a target of the investigation when you brought him to the grand jury?" The prosecutor replied that although the defendant's inconsistencies in his earlier statements to police made him "a person of interest" -- "[t]here were things that weren't adding up ... that he seemed to know a lot more than he was letting on. And so that was the nature of our inquiry with [the defendant]" -- the Commonwealth did not consider him a "target" until additional "witnesses came in and testified about threatening statements ... that [the defendant] had made to [the victim], and additional information was gathered about [the defendant] as the investigation went on in subsequent months leading up to [the] October" indictment. The prosecutor added that had the defendant been a target, he would have received a letter informing him of that status.
On May 6, 2009, the trial judge issued an oral ruling denying the defendant's motion. He found that "[b]ased upon the evidence before [him], the defendant ... was not a target, but [the Commonwealth] believed that he knew more than he told and he was not being fully truthful."4 The judge also found that the defendant was *965not under the influence of drugs or alcohol, threatened, coerced, or offered false promises when appearing before the grand jury, and "was treated appropriately," such that his testimony was free and voluntary under the totality of the circumstances.
5. Defendant's direct appeal. At trial, the jury found the defendant guilty of murder in the first degree. On direct appeal, he continued to press his objection to the introduction of his grand jury testimony, arguing that it infringed on his "federal and state law rights against compelled self-incrimination." We rejected the argument that self-incrimination warnings were legally required at the time, thus upholding the trial judge's denial of the defendant's motion in limine. Woods I, 466 Mass. at 716-720, 1 N.E.3d 762. We discerned no error in the trial judge's finding that the defendant was not a target, and added that "[e]ven if the defendant were a 'target,' the Commonwealth was under no obligation to warn him of that status" under Federal or State law. Id. at 717, 1 N.E.3d 762, citing United States v. Washington, 431 U.S. 181, 188-190, 97 S.Ct. 1814, 52 L.Ed.2d 238 (1977), and Commonwealth v. D'Amour, 428 Mass. 725, 743, 704 N.E.2d 1166 (1999).
We then "consider[ed] for the first time" what we perceived as "the defendant's separate argument that the Commonwealth must advise targets or potential targets of the grand jury's investigation of their right not to incriminate themselves." Woods I, 466 Mass. at 717-718, 1 N.E.3d 762. Concluding that a grand jury summons "is a form of compulsion," we "adopt[ed] a rule that where, at the time a person appears to testify before a grand jury, the prosecutor has reason to believe that the witness is either a 'target' or is likely to become one, the witness must be advised, before testifying, that (1) he or she may refuse to answer any question if a truthful answer would tend to incriminate the witness, and (2) anything that he or she does say may be used against the witness in a subsequent legal proceeding" (footnote omitted). Id. at 719-720, 1 N.E.3d 762.5 We clarified that the rule is nonconstitutional and therefore "is only required to be applied prospectively." Id. at 720, 1 N.E.3d 762.
6. Motion for a new trial. The defendant subsequently moved for a new trial, where he focused primarily on refuting the trial judge's factual determination that he was not a target of the investigation.6 The defendant attached the grand jury testimony of the four witnesses who had testified before the defendant during the grand jury investigation, but whose testimony was largely unknown to the trial judge, and therefore was not a part of the record in Woods I.7 Two of those witnesses --*966Sheff and Derochea -- testified to hearsay statements they had heard about threats the defendant had made against the victim before the shooting. The motion judge agreed that the grand jury testimony of these two witnesses constituted "substantial evidence" linking the defendant to the crime, thus rendering him "a target or potential target of the investigation." The judge declined to grant the defendant a new trial on that basis, however, concluding that this court's decision in Woods I was not dependent on the factual finding that the defendant was not a target of the investigation.
Discussion. A single justice's determination that a petition raises a "new and substantial question" under G. L. c. 277, § 33E, is "final and unreviewable." Commonwealth v. Scott, 437 Mass. 1008, 1008, 770 N.E.2d 474 (2002). We review the denial of the defendant's motion for a new trial for "a significant error of law or other abuse of discretion" (citation omitted). Commonwealth v. Acevedo, 446 Mass. 435, 441, 845 N.E.2d 274 (2006). The defendant argues that the motion judge made such an error in concluding that this court's decision in Woods I upholding the admission of the defendant's grand jury testimony did not depend on the factual finding that the defendant was not a target of the investigation. The motion judge did not err.
First, the language of Woods I makes clear that the motion judge was correct. On direct appeal, the defendant raised the very same legal argument that he puts before us now: because he was a target of the grand jury, he was entitled to self-incrimination warnings. The court specified in Woods I, 466 Mass. at 717, 1 N.E.3d 762, that "[e]ven if the defendant were a 'target,' the Commonwealth was under no obligation to warn him of that status" (emphasis added). Likewise, addressing "the defendant's separate argument" regarding self-incrimination warnings, the court acknowledged that it was considering the issue "for the first time" -- meaning that nothing prior to Woods I required self-incrimination warnings as a matter of law. Id. at 717-718, 1 N.E.3d 762. In other words, just as the Commonwealth was under no obligation to warn the defendant of his target status, even if he were a target, so too was the Commonwealth under no obligation at that time to advise the defendant of his right against self-incrimination. The court adopted that very requirement in the defendant's case, and stated that it was to apply only prospectively, "to grand jury testimony elicited after the issuance of the rescript in [that] case." Id. at 720, 1 N.E.3d 762. Thus, irrespective of the defendant's target status, he was not entitled to the new rule.8
*967As the motion judge recognized, the sole difference between the defendant's argument on direct and his argument on collateral review is the factual basis for his claim that he was a target: now, in addition to his own testimony, he offers the testimony of the four witnesses who appeared before him during the grand jury investigation (and whose testimony the motion judge deemed "substantial evidence" establishing that the defendant was a target). At the core of the defendant's instant argument are the dual suggestions that, had the trial judge been made aware that two witnesses (Sheff and Derochea) testified at the grand jury before the defendant did, regarding prior threats the defendant had made against the victim, the trial judge (1) would have found that the defendant was a "target" by the time he testified, and (2) would have granted on that basis the defendant's motion to exclude the defendant's grand jury testimony.
We are in no position to engage in such speculation. First, the fact that the motion judge concluded, based on this new testimony, that the defendant was a target does not automatically establish that the trial judge would have reached the same conclusion. Both Sheff and Derochea's testimony involved hearsay, and this may well have affected the weight that the trial judge would have assigned their testimony when determining whether it constituted "substantial evidence" that the defendant was a target when he testified.9 It was not until after the defendant testified that the grand jury heard from additional witnesses who described hearing the defendant's threats firsthand.
Second, even assuming that the trial judge would have concluded based on this additional testimony that the defendant was a target, we cannot say that he would have excluded the defendant's grand jury testimony on that basis. The defendant focuses extensively, and exclusively, on the trial judge's comment at the motion in limine hearing that the defendant's status as a target "would change the whole way that [he would] have to view this" issue. What the defendant omits is the trial judge's additional comment, made at the very outset of the hearing, that he had not yet researched the law regarding the defendant's position that target warnings were required. As our above discussion makes clear, had the trial judge done so, he would have discovered that such warnings were not legally required at that time, and thus the Commonwealth's failure to provide the defendant with such a warning did not preclude them from using that testimony at trial.
Conclusion. We decline to grant the defendant a new trial on collateral review based on an alleged violation of a right that simply did not exist at the time of his *968trial.10 We affirm the denial of the defendant's motion for a new trial.
So ordered.