DUFFLY, J.

In April, 1999, Stanley Donald was convicted by a Superior Court jury on two indictments charging aggravated rape, as well as indictments charging unarmed robbery, kidnapping, carjacking, and assault and battery by means of a dangerous weapon.1 Evidence at trial indicated that Donald's deoxyribonucleic acid (DNA) profile matched that of sperm found on underwear worn by the victim on the day of the offense. For approximately ten years, Donald has sought, unsuccessfully, to have the sperm sample analyzed with a newer and more sophisticated technique for DNA testing; he also has requested that initial DNA tests be performed on other biological evidence. Following the Legislature's enactment of G. L. c. 278A, "An Act providing access to forensic and scientific evidence," see St. 2012, c. 38, Donald filed two motions pursuant to G. L. c. 278A, § 3 (§ 3 motions), again seeking the more sophisticated DNA testing. A Superior Court judge denied his first motion on the ground that DNA testing already had been conducted, and also denied his renewed motion, noting that the evidence against Donald was overwhelming. Donald appealed from the denial of his renewed § 3 motion, and we granted his application for direct appellate review.

In Commonwealth v. Wade, 467 Mass. 496, 501-506 (2014), we considered the threshold requirements that must be met by a party seeking scientific testing or forensic analysis pursuant to G. L. c. 278A, § 3, and the standard for determining whether those requirements have been met. That case, however, did not present the question with which we are confronted here: whether G. L. c. 278A permits access to scientific testing where such testing previously has been conducted using a less advanced technique. We conclude that it does, and therefore, to the extent that the judge denied Donald's motion on the ground that an older form of DNA testing previously had been conducted, the denial was error. Because Donald's motion does not contain information demonstrating that the requested analysis was not developed at the time of his conviction, however, and provides no other explanation why the requested testing was unavailable at trial, see G. L. c. 278A, § 3 (b) (5), we affirm the denial of the motion, on grounds different from those relied upon by the motion judge. See Commonwealth v. Va Meng Joe, 425 Mass. 99, 102 (1997).

Background. On the morning of October 21, 1997, the victim was accosted in the parking lot of her apartment building by an African-American male whom she later identified as the defendant.2 He demanded cash, took her keys, and ordered her into her vehicle. The man got into the driver's seat of the vehicle, drove some distance, and repeatedly threatened her. He also took her driver's license and bank access card, and obtained the password for that card. He then parked in a secluded area. There, he pulled the victim out of her vehicle, physically assaulted her, and demanded that she take off her clothes. He raped the victim, penetrating her vagina with his tongue and penis, and drove off in the victim's automobile, leaving her behind. The victim was taken to a hospital where she was treated for her injuries and a "rape kit" was obtained.3

Donald was identified as the individual who, a short time after the rape, used the victim's bank access card to withdraw cash from an automated teller machine located four miles from the scene of that crime. Police located the victim's vehicle about twenty miles from the scene; Donald's driver's license was found approximately fifty yards from the vehicle. A cutting from the victim's underwear was submitted to a private laboratory for DNA testing. Analysts at that laboratory compared the DNA profile of the sperm samples from the cutting with Donald's DNA profile using the polymerase chain reaction (PCR) method of DNA testing.4 This yielded a DNA profile that occurs in one in 7,800 African Americans, and from which Donald could not be excluded. Neither the evidence in the rape kit nor any piece of physical evidence other than the victim's underwear has been subjected to DNA testing.

Beginning in 2001, for the most part proceeding pro se but intermittently represented by counsel, Donald has sought to have DNA testing performed on certain portions of the evidence, including the victim's underwear, often through motions for a new trial pursuant to Mass. R. Crim. P. 30, as appearing in 435 Mass. 1501 (2001). He also has sought funds for DNA testing, and discovery concerning the biological evidence recovered at the scene. With the exception of a motion to preserve evidence, all such motions have been denied.5

In 2012, Donald, acting pro se, sent a letter to a Superior Court judge seeking to obtain DNA testing pursuant to G. L. c. 278A. Treating that letter as a § 3 motion, the judge, who was not the trial judge, denied the motion on the ground that Donald had not complied with G. L. c. 278A § 3 (b); in a margin notation, she "note[d], in particular," that DNA testing had been performed and that the test results had been admitted at trial. Thereafter, represented by appointed counsel, Donald filed a § 3 motion that was denied by the same judge, citing the previous denial. Donald then filed a renewed § 3 motion, providing additional information and requesting that, if the motion were again denied, the judge identify "the specific failure resulting in denial." The judge denied the renewed motion, referencing her earlier denial and stating also that "the evidence against the defendant (excluding DNA evidence) was overwhelming." Donald appealed from that denial,6 and we granted his application for direct appellate review.

Discussion. This case is controlled in many respects by our decision in Commonwealth v. Wade, supra. The determination whether a motion for scientific testing meets the requirements of G. L. c. 278A, § 3, the initial stage of a two-part process, is a "limited, threshold inquiry." Commonwealth v. Wade, supra at 505. In order to proceed to the second stage of that process, an evidentiary hearing, a moving party is required to provide information demonstrating that he or she meets the requirements of G. L. c. 278A, § 3 (b), and to submit an affidavit as required by G. L. c. 278A, § 3 (d). See Commonwealth v. Wade, supra at 502-503. At this preliminary stage, a moving party is required only to point to the existence of specific information that satisfies the statutory requirements. See Commonwealth v. Wade, supra at 503-504. Compare G. L. c. 278A, § 3 (b), with G. L. c. 278A, § 7 (b) (at hearing pursuant to G. L. c. 278A, § 7, moving party must make evidentiary showing by preponderance of evidence). See note 12, infra.

The judge who denied Donald's renewed motion for DNA testing did not state explicitly which of the provisions of G. L. c. 278A, § 3, the motion failed to meet. However, the judge took note of the weight of the evidence introduced against Donald at trial, as well as the fact that DNA testing previously had been performed and the test results admitted at Donald's trial. In determining whether a § 3 motion meets the statutory requirements, a judge should not "consider the relative weight of the evidence or the strength of the case presented against the moving party at trial." Commonwealth v. Wade, supra at 505-506. Here, the judge did consider, and apparently rely on, the weight of the evidence supporting Donald's conviction. We review Donald's motion de novo to determine whether it satisfies the statutory requirements. See id. at 506.

Donald's renewed § 3 motion requests that biological evidence be subjected to "DNA testing methods provided by Profiler Plus and Cofiler," and references attached documents that contain the manufacturer's descriptions of the "AmpFlSTR Profiler Plus ID PCR Amplification Kit" (Profiler Plus kit) and the "AmpFlSTR Cofiler PCR Amplification Kit" (Cofiler kit). The motion cites Commonwealth v. Gaynor, 443 Mass. 245, 266 (2005), in which we affirmed the admissibility of test results obtained from Profiler Plus and Cofiler kits. The biological evidence that Donald seeks to have tested includes a saliva sample, head hairs, and pubic hairs collected from the victim and included in the rape kit, as well as a cutting from the victim's underwear. The motion notes that this material has been logged as evidence by the Boston police department and has been preserved.7 The renewed motion incorporates an affidavit in which Donald avers, "I have steadfastly maintained my innocence in this case," and states that DNA testing "will exonerate me as the source of the sperm found by the Commonwealth." The motion therefore satisfies G. L. c. 278A, § 3 (b) (1)-(3), (d). See Commonwealth v. Wade, supra at 506 n.11, 512.

The motion also satisfies the requirement of G. L. c. 278A, § 3 (b) (4),8 with respect to testing of sperm on the underwear cutting, and of saliva and hair in the rape kit.9 The motion refers to an attached letter written by Dr. Donald E. Riley, a DNA consultant at the University of Washington, in which Riley states that "[t]he newer DNA testing format, using Profiler Plus and Cofiler, is more powerful statistically than PM plus DQA1 that was used previously in [Donald's] case." Riley also states that "some cases have been reversed on that basis."

Donald's renewed § 3 motion incorporates his earlier § 3 motion, which explained, with references to expert testimony at trial, that based on DNA testing of the sperm found on the victim's underwear, Donald could not be excluded as a source of the sperm. The motion states that Donald's conviction therefore "rested in part on identification by DNA evidence," and asserts that "the more sophisticated tests available now ... offer the potential to result in evidence that is material to [Donald's] identification as the perpetrator." This information suffices to demonstrate that the requested testing to be performed on the underwear, saliva, and hair has the potential to produce a DNA profile that fails to match, or does match, Donald's DNA profile, and is therefore material to identifying him as the perpetrator of the rape. Contrary to the Commonwealth's contention, the weight of the evidence against Donald is not relevant to a determination that testing has the potential to produce a result that is material to his identification as the perpetrator of the offense. See Commonwealth v. Wade, supra at 508.

We turn therefore to a consideration whether G. L. c. 278A permits a moving party access to a more advanced form of a particular scientific test, such as DNA testing, where an older version of such a test previously has been conducted. General Laws c. 278A, § 3 (b) (5), requires that a moving party provide "information demonstrating that the evidence or biological material has not been subjected to the requested analysis" for one of five enumerated reasons.10 Donald's motion cites only one of the five enumerated reasons; it purports to provide information demonstrating that "the requested analysis ... had not yet been developed at the time of the conviction." See G. L. c. 278A, § 3 (b) (5) (i). As discussed, although the motion includes sufficient threshold information that the evidence has not been subjected to the requested analysis, it does not provide information demonstrating that the requested analysis had not been developed at the time of Donald's conviction.

1. Whether evidence previously was subjected to analysis that is different from requested analysis. In his motion, Donald acknowledges that results from DNA testing of the underwear cutting using the PM plus DQA1 format were presented at trial, and requests that DNA testing now be conducted using the newer Profiler Plus and Cofiler tests. The Commonwealth maintains that the underwear cutting has been subjected to the requested analysis because the Profiler Plus and Cofiler tests are "merely a more refined version" of DNA testing presented at trial. We reject the Commonwealth's contention that a moving party who seeks testing of evidence that previously has been subjected to testing using an older version of the requested technology cannot meet the requirement of G. L. c. 278A, § 3 (b) (5).

In order to satisfy the requirement that evidence has not been subjected to the requested analysis, where an older version of the requested testing has been used, a moving party must provide information demonstrating that the requested analysis offers a material improvement over any previously conducted analysis in accurately identifying or excluding the party as the perpetrator of the crime. There are a number of different ways in which a test may have improved materially in accuracy; accordingly, several types of information may suffice to demonstrate that the requested analysis offers a material improvement. A moving party might meet this requirement, for example, by offering information that the requested analysis uses a different technology that is designed to reduce error, or applies a more comprehensive technique, or offers a significant increase in statistical accuracy.11 Whether a test offers a material improvement in accuracy over a previous test will require a case-specific inquiry, both because of the many ways in which testing may be improved and because of differences in the types of forensic testing and analyses, such as DNA testing or fingerprint analysis, that a moving party may seek.12

Donald's motion proffers two pieces of information, each of which, independently, would suffice to provide information demonstrating that the requested analysis offers a material improvement in accuracy over the previously conducted testing. First, the motion references Riley's attached letter stating that testing using Profiler Plus and Cofiler "is more powerful statistically than PM plus DQA1 that was used previously in [Donald's] case" and that "some cases have been reversed on that basis."13 Second, documents attached to Donald's motion describe the technique used by Profiler Plus and Cofiler and state that they combine the PCR-based method and short tandem repeat (STR) analysis14 to "generate information for all [thirteen] core STR loci[15] required by the Combined DNA Index System (CODIS) database."16 According to expert testimony at Donald's trial, the previous testing analyzed only six loci.17 Whereas the analysis using six loci showed that Donald was among one in 7,800 African Americans whose DNA profile would match that of sperm obtained from the underwear, analysis using thirteen STR loci has the potential to result in random match probabilities on the order of one in several trillion or quadrillion. See, e.g., Commonwealth v. Dixon, 458 Mass. 446, 450 n.13 (2010) (STR DNA testing on thirteen loci can generate match probability of one in 575 trillion Caucasian Americans); Commonwealth v. Gaynor, 443 Mass. 245, 248 (2005) (STR DNA testing on thirteen loci generated match probability of one in 64 quadrillion African Americans); Harvey v. Horan, 285 F.3d 298, 305 n.1 (4th Cir. 2002) (order denying rehearing en banc) (Lutting, J., concurring) (reviewing literature on STR DNA testing using thirteen loci and noting that this type of testing places probability of random match in general order of one in 100 billion to one in 1 quadrillion).

In enacting G. L. c. 278A, the Legislature clearly intended to allow access to more sophisticated forensic and scientific tests than were available at the time of a moving party's trial. The legislative findings that accompanied both the House and Senate versions of the proposed act recognized that the accuracy of forensic testing techniques can improve over time, and that these advancements can play a significant role in correcting wrongful convictions based on older, less sophisticated testing. See 2011 Senate Doc. No. 753; 2011 House Doc. No. 2165 (as forensic and scientific "techniques become more accurate, their use can, in some cases, conclusively establish a person's guilt or innocence"; purpose of G. L. c. 278A "is to remedy the injustice of wrongful convictions of factually innocent persons by allowing access to analyses of biological material with newer forensic and scientific techniques").

In light of this legislative intent, we conclude that a § 3 motion should not be denied on the ground that the evidence sought to be tested has been subjected previously to a method of testing, if the accuracy of that testing has materially improved the test's ability to identify the perpetrator of a crime. To the extent that the judge denied Donald's motion solely on the ground that DNA testing previously had been conducted, the denial was error. For the reasons stated, Donald's motion provides information demonstrating that the testing he seeks using the Profiler Plus and Cofiler format offers a material improvement in accuracy compared to the DNA testing that was previously conducted.

2. Whether requested analysis had not been developed at time of conviction. Donald's renewed § 3 motion does not, however, provide information demonstrating why the more advanced testing he requests was not conducted at the time of conviction. The motion states that it meets the requirement of G. L. c. 278A, § 3 (b) (5), because the Profiler Plus and Cofiler tests "had not yet been developed at the time of conviction," see G. L. c. 278A, § 3 (b) (5) (i), but it provides no information to support that statement.18 On its face, G. L. c. 278A, § 3 (b) (5) (i), does not set forth the type of information that will suffice to demonstrate that the requested analysis was not developed at the time of conviction. The threshold requirement of G. L. c. 278A, § 3 (b) (5), might be satisfied in a number of ways. The § 3 motion might, for example, include citations to existing case law, a court order, or a scholarly article, or attach a letter or affidavit from an expert in the field in which the testing is sought, containing the information that the requested analysis was not available at the time of conviction.19

As with all of the requirements in G. L. c. 278A, § 3 (b), a party seeking to show that the requested analysis was not developed at the time of conviction bears no burden of establishing that fact by a preponderance of the evidence. Compare G. L. c. 278A, § 3 (b), with G. L. c. 278A, § 7 (b). In order to survive to the hearing stage, however, a § 3 motion must do more than merely recite the elements of G. L. c. 278A, § 3 (b) (5) (i). Donald's motion, which states only that it satisfies the requirements of that section and provides no information to support this bare contention, fails to do so.

Conclusion. The order denying the renewed G. L. c. 278A, § 3, motion is affirmed.

So ordered.