Botsford, J.
We consider whether the Commonwealth, in a criminal case, may seek the production of records from a third party in advance of trial or an evidentiary hearing by issuing a subpoena duces tecum directly to the party under G. L. c. 277, § 68, or whether it must first obtain judicial approval, pursuant to Mass. R. Crim. P. 17 (a) (2), 378 Mass. 885 (1979), as construed by Commonwealth v. Jjimpron, 441 Mass. 265, 268-271 (2004) (Lampron). We conclude that it must first obtain judicial approval.1
Background. On January 19, 2007, the defendant, then sixteen years of age, was arraigned in the District Court on charges of murder in the first degree and related offenses in the stabbing death of a fellow student at Lincoln-Sudbury High School. He was ordered held without bail in the Department of Youth Services secure unit at the Plymouth County correctional facility (facility). A probable cause hearing was scheduled for March 5, 2007. See Mass. R. Crim. P. 3 (f), as appearing in 442 Mass. 1503 (2004).
On February 9, 2007, the district attorney for the northern district (district attorney or Commonwealth) issued a subpoena duces tecum to the facility’s keeper of records, seeking “any books, papers, visitor log, taped phone calls, and pin list”2 for the period from January 19 to February 12, 2007.3 The subpoena directed the keeper of records to produce the requested materials in person at the March 5 probable cause hearing, or, “[i]n lieu of a court appearance,” to “provide the requested records prior to” [173]*173March 5. A handwritten note accompanying the subpoena requested the records be mailed to the district attorney’s office. Within a couple of days of receiving the subpoena, the facility’s telephone administrator copied the recordings from the telephone system’s computer hard drive onto a compact disc and mailed it to the district attorney’s office.
On various dates between February 13 and March 1, 2007, the Commonwealth presented evidence of the stabbing to a grand jury, which indicted the defendant for murder in the first degree on March 1, 2007. Accordingly, the scheduled probable cause hearing in the District Court never took place; on March 14, the Commonwealth entered a nolle prosequi on the charges in that court.
Thereafter, the Commonwealth issued to the keeper of records three more subpoenas — on April 2, May 14, and July 26, 2007 — collectively requesting recordings of the defendant’s telephone calls for the period from February 13 to July 31, 2007.4 The return dates for two of the three subpoenas coincided, respectively, with a case status conference in the Superior Court (April 30) and a pretrial conference in that court (May 30); the return date for the third subpoena (July 31) was not connected to any court hearing. Each of the three subpoenas (like the February subpoena) stated that the requested materials could be provided before the return date. Within one or two days of receiving each subpoena, the keeper of records mailed compact disc recordings of the requested telephone calls to the district attorney’s office.5 According to the defendant, the subpoenaed recordings include over 2,000 minutes (33.3 hours) of conversations over a period of 191 days, the “vast majority of which” were between him and his parents and brother; some involved friends. On June 12, 2007, the Commonwealth provided the defendant copies of the recordings obtained through the February, April, and May subpoenas, pursuant to Mass. R. Crim. P. 14 (a) (1) (A), as appearing [174]*174in 442 Mass. 1518 (2004). As for the recordings obtained through the July subpoena, the Commonwealth provided them to the defendant some time between January and April, 2008. Trial was scheduled for September 15, 2008.
In January, 2008, the defendant notified the Commonwealth of his intent to rely on a defense of lack of criminal responsibility because of mental disease or defect. See Mass. R. Crim. P. 14 (b) (2) (A), as appearing in 442 Mass. 1518 (2004). In April, 2008, the defendant, asserting that the Commonwealth had informed him of its intent to search the subpoenaed recordings for evidence of criminal responsibility, moved to suppress the recordings. The defendant claimed that the Commonwealth lacked authority to issue the subpoenas without first obtaining judicial approval pursuant to Mass. R. Crim. P. 17 (a) (2),6 as construed by Lampron, 441 Mass. at 268-271 (only judge can issue subpoena for records before trial pursuant to motion by requesting party, supported by affidavit, showing relevance, admissibility, necessity, and specificity).7 The Commonwealth countered that it was empowered to issue the subpoenas on its own, pursuant to G. L. [175]*175c. 277, § 68,* ***8 and that, even were judicial approval required, it would be entitled to such approval.9
At the outset of the hearing on the defendant’s motion, the judge (with the parties’ agreement) decided to focus on whether the Commonwealth had erred in failing to comply with the requirements of rule 17 (a) (2) and Lampron because if so, the judge reasoned, the subpoenas would have issued improperly, and thus the judge would not need to address the defendant’s constitutional claims. The judge added that, were he to conclude that the Commonwealth had erred in failing to comply with the requirements of rule 17 and Lampron, it would still be entitled, in a future motion, to seek to satisfy those requirements.
On May 14,2008, following the hearing (at which the facility’s telephone system administrator was the sole witness), the judge allowed the defendant’s motion to suppress. He concluded that the Commonwealth had erred in failing to seek prior judicial approval before issuing the subpoenas, and ordered the parties to turn over all copies of the recordings and associated documents to the clerk of the Superior Court, where they would be impounded.
Subsequently, the Commonwealth moved under rule 17 and Lampron for judicial approval to subpoena a portion of the recordings it had originally sought, namely, recordings of the defendant’s telephone calls from January 19 to March 6, 2007. On May 23, 2008, the judge found the Commonwealth had failed to satisfy the requirements of Lampron and denied the motion. He said, however, that closer to trial he would be willing to revisit the Commonwealth’s attempt to subpoena the telephone calls, further noting that any future attempt by the Commonwealth to subpoena [176]*176the recordings would be subject to a possible motion to quash as well as to the defendant’s constitutional challenges.
Thereafter, the Commonwealth filed a petition under G. L. c. 211, § 3, in the county court, seeking review by a single justice of the denial of its Lampron motion. Alternatively, it requested leave to pursue an interlocutory appeal from the allowance of the defendant’s motion to suppress. See Mass. R. Crim. P. 15 (a) (2), as appearing in 422 Mass. 1501 (1996). The single justice denied the Commonwealth’s petition (from which the Commonwealth did not appeal),10 but granted it leave to pursue an interlocutory appeal from the suppression ruling. We agree with the Superior Court judge that the Commonwealth was required to comply with rule 17 and to obtain prior judicial approval in seeking the defendant’s telephone records from the jail, but we do not agree that suppression of the records is required because of the Commonwealth’s error. The defendant, however, may still pursue the constitutional challenges that the judge deferred.11
Discussion, a. Defendant’s standing. The Commonwealth claims the defendant lacks standing to challenge the issuance of the subpoenas because the subpoenas concern telephone records of a third party, the facility, and because in any event the defendant had no reasonable expectation of privacy in his telephone calls. We disagree. Although the recordings are, in a proprietary sense, those of the facility rather than the defendant, the defendant has a direct interest in them because they consist of his own conversations with family and friends.12 Moreover, the defendant, as a party to this criminal case, has a special concern with ensuring that the Commonwealth abide by the rules of criminal procedure, and the facility cannot reasonably be relied on in these circumstances to vindicate that concern. Cf. Commonwealth v. [177]*177Lam, 444 Mass. 224, 228-229 (2005) (Commonwealth had standing to object to defendant’s motion to issue subpoenas to third parties where Commonwealth had interest in ensuring compliance with rule 17 [a] [2]’s prohibition against using rule as discovery device or for fishing expedition, and had interest in protecting its witnesses from harassment by improper discovery requests); United States v. Noriega, 764 F. Supp. 1480, 1493 (S.D. Fla. 1991) (court’s ability to ensure against abuse of subpoenas duces tecum “assumes that the recipient of the subpoena has some interest or incentive in filing” motion to quash or modify; “it is wishful thinking to expect that prison officials will either oppose a government-requested subpoena which implicates an incarcerated defendant’s interests or else enable the defendant to file his own motion to quash by notifying him that such subpoenas have been issued”)13; State v. Barreiro, 432 So. 2d 138, 139 n.1 (Fla. Dist. Ct. App. 1983) (defendant “has standing to move to quash a subpoena duces tecum served on a third-party corporation based on his status as a defendant complaining of a violation of the criminal procedure rules”).14 The defendant has standing.
[178]*178b. Historical development of criminal subpoenas. Before we address the Commonwealth’s claims concerning its subpoena power, it is useful first to examine the development of our law governing criminal subpoenas.
1. Subpoenas by statute and rule. General authority for issuing subpoenas in criminal cases is granted by G. L. c. 233, § 115; G. L. c. 277, § 68 (see note 8, supra); and Mass. R. Crim. P. 17, 378 Mass. 885 (1979) (see note 6, supra). See Application of a Grand Jury of N.Y., 8 Mass. App. Ct. 760, 764 (1979). We consider the evolution of those authorities.
The earliest statutory authority for issuing criminal subpoenas — a precursor to G. L. c. 233, § 1 — granted such power to justices of the peace. See St. 1783, c. 51, § 2 (justices of peace “authorized and impowered to grant subpoenas for witnesses in all criminal causes pending before” various courts). A subsequent version of that statute provided that, unless in connection with a “complaint brought before himself,” a justice of the peace could issue a subpoena in a criminal case only at the “request” of a prosecutor or defendant for “witnesses to appear at any court ... to give evidence.” St. 1791, c. 53.16 Neither prosecutors nor defendants were statutorily required, however, to obtain leave from a justice of the peace, but merely had to “request” the issuance of a subpoena. The same is true today, under G. L. c. 233, § 1. See Commonwealth v. Mitchell, 444 Mass. 786, 791-792 n.12 (2005). But neither G. L. c. 233, § 1, nor its predecessors expressly authorize the issuance of subpoenas in advance of trial or an evidentiary hearing.
Through a recodification of the Massachusetts statutes in 1836, justices of the peace retained their authority to issue subpoenas at [179]*179the request of prosecutors and defendants, see R.S. (1836), c. 85, § 39, but for the first time prosecutors were given independent statutory authority to issue subpoenas under their own signatures. See R.S. (1836), c. 136, § 25. That statute, substantively identical to its modem incarnation, G. L. c. 277, § 68, meant not only that a prosecutor was no longer required to “request” that a justice of the peace issue a subpoena for a witness or records, but also that, in the context of a grand jury investigation, a prosecutor was not required to obtain prior approval from the grand jury to issue a subpoena. See 1 S.S. Beale, W.C. Bryson, J.E. Felman & M.J. Elston, Grand Jury Law and Practice § 6:2, at 6-13 (2d ed. 2008) (G. L. c. 277, § 68, “allow[s] the prosecutor to exercise the subpoena power without the grand jury’s prior approval”). See also Massachusetts Superior Court Criminal Practice Manual § 1.6.8 (a) (Mass. Continuing Legal Educ. 1999 & Supps. 2003, 2006) (witnesses may be summoned to testify before grand jury by members of grand jury or prosecutor).17 As with G. L. c. 233, § 1, however, G. L. c. 277, § 68, which speaks of subpoenas for witnesses “to appear and testify” (see note 8, supra), makes no reference to issuing subpoenas in advance of trial or an evidentiary hearing.18
Following the 1836 recodification of our statutes, the next major development in our law of criminal subpoenas came in 1979, with the promulgation of the Massachusetts Rules of Criminal Procedure, 378 Mass. 842 (1979). The Reporters’ Notes to Mass. R. Crim. P. 17 explain that the mie “is for the most part in [180]*180accord with prior Massachusetts law,” and refer specifically to G. L. c. 233, § 1. Reporters’ Notes to Mass. R. Crim. P. 17, Mass. Ann. Laws, Rules of Criminal Procedure, at 1521-1522 (LexisNexis 2008). The “prototype” for our rule 17 was Fed. R. Crim. P. 17 (Federal Rules of Criminal Procedure became effective in 1946).19 See Reporters’ Notes to rule 17, supra. See also Lampron, 441 Mass. at 270 (“Because our rule was modeled after Fed. R. Crim. P. 17 [c] and is intended to address the same circumstances, we adopt the standards articulated by the Federal courts regarding the issuance of a subpoena for production of documentary evidence”). We now examine rule 17’s connection to prior Massachusetts law, and consider how Federal courts have interpreted the cognate Federal rule.
2. Rule 17 subpoenas. Rule 17 (a) (1) and (2) — consistent with G. L. c. 233, § 1, and G. L. c. 277, § 68 — empower a court clerk or any person authorized by statute to issue a summons,20 without prior judicial approval, for a witness to “attend and give testimony” and produce “books, papers, documents, or other objects” (collectively, records) at a trial or evidentiary hearing. See Commonwealth v. Mitchell, 444 Mass. at 791-792 n.12; [181]*181Lampron, supra at 270 (role 17 [a] [2] authorizes issuance of summons “for a trial or evidentiary hearing”). See also 25 Moore’s Federal Practice par. 617.02[1], at 617-6-617-7, and par. 617.08[1], at 617-19 (3d ed. 2009) (under Fed. R. Crim. P. 17 [a] and [c] [1], subpoena may issue for witness’s appearance, including records, “at any type of criminal proceeding in which evidence may be adduced,” such as before grand jury, at trial, or at defendant’s competency or detention hearing); K.M. Brinkman & G. Wiessenberger, Federal Criminal Procedure: Litigation Manual at 206 (2008) (“Rule 17 provides procedures for obtaining witness testimony and tangible evidence by subpoena for grand jury, trial, Rule 15 depositions [compare Mass. R. Crim. P. 35, 378 Mass. 906 (1979)], and pretrial and post-trial hearings such as preliminary examinations, suppression hearings, and sentencing hearings. Rule 17 cannot be used to conduct discovery”).
Where role 17 (a) (2) departs from earlier Massachusetts law is in authorizing the production of subpoenaed records “within a reasonable time prior to the trial or . . . when they are to be offered in evidence” (emphasis added), when the court so directs. The change was “not intended to permit the use of summonses to subvert the discovery role, Mass. R. Crim. P. 14,” as amended, 444 Mass. 1501 (2005), but “to permit the court to avoid delay where the production of many books, papers, documents, or other objects would delay the proceedings if not ordered until the . . . commencement” of the trial or evidentiary hearing. Reporters’ Notes to Mass. R. Crim. P. 17 (a) (2), supra at 1522. Accord Commonwealth v. Mitchell, supra at 791. See 2 C.A. Wright, Federal Practice and Procedure § 274, at 241-242 & n.15 (3d ed. 2000) (although most of Federal role 17 [c] “was a restatement of prior law,” its allowance of either side to inspect subpoenaed records “prior to the trial” was “an innovation,” meant to expedite trial by providing time and place before trial for inspection of subpoenaed materials).
Unlike role 14, which governs discovery between the parties, role 17 allows for pretrial access to records from third parties. See Commonwealth v. Dwyer, 448 Mass. 122, 140 n.22 (2006); Lampron, 441 Mass. at 268. That access is potentially available to both prosecutors and defendants. See Martin v. Commonwealth, 451 Mass. 113, 123 n.20 (2008); Commonwealth v. Draheim, 447 Mass. 113, 118 n.12 (2006); Commonwealth v. Mitchell, 444 [182]*182Mass. at 798 n.17; Lampron, supra at 268-270. See also 2 C.A. Wright, Federal Practice and Procedure, supra at § 274, at 240 (government as well as defendant may use Federal rule 17 [c]); 5 W.R. LaFave, J.H. Israel, N.J. King, & O.S. Kerr, Criminal Procedure § 20.2(d), at 371 (3d ed. 2007) (referring to use of Federal rule 17 [c] by both prosecutors and defendants for pretrial production of records).
In Lampron, we concluded that a party seeking pretrial production of third-party records must file a motion seeking prior judicial approval. See Lampron, 441 Mass. at 270 (only judge has authority, on filing of motion, to issue subpoena for records prior to trial).21 Once a subpoena has issued, it may be challenged by a motion to quash or for modification. See id. at 267-268. Accord Commonwealth v. Mitchell, 444 Mass. at 798-799.
[183]*183As for the standard that a party must satisfy in seeking the issuance of a pretrial subpoena, in Lampron we adopted the standard used by Federal courts in connection with subpoenas issued pursuant to Federal rule 17 (c). See Lampron, 441 Mass. at 269-270 (adopting standard used in United States v. Nixon, 418 U.S. 683, 699-700 [1974]).22 We said in Lampron that “the relevancy determination” set forth in the first prong of the Nixon test, see note 22, supra, “must be satisfied before any documents of any kind may be summonsed from nonparties” (emphasis added). Lampron, supra at 268. Moreover, the requirement that a party seek prior judicial approval “must be followed whenever any documents, including documents likely to be privileged, are sought prior to trial” (emphasis added). Id. at 270, citing Commonwealth v. Bishop, 416 Mass. 169, 185-186 (1993) (discussing defendant’s request for unprivileged school attendance records). Accord Commonwealth v. Dwyer, 448 Mass. at 140. With these legal principles in mind, we now address the Commonwealth’s claims regarding its subpoena.
c. Commonwealth’s subpoena. The Commonwealth raises several claims regarding the use of its subpoena power in this case. First, it contends that it was authorized, under G. L. c. 277, § 68, to issue the February subpoena without seeking prior judicial approval under Lampron because G. L. c. 277, § 68, authorizes it to subpoena any third-party records as long as the return date coincides with an evidentiary hearing, as the return date for the February subpoena did: it coincided with the scheduled (although not held) probable cause hearing.23 We disagree. The [184]*184subpoena was invalid because it allowed the keeper of records to provide the recordings in advance of the probable cause hearing, contrary to the language and historical development of G. L. c. 277, § 68, discussed supra, which indicate the records should be produced only at an evidentiary hearing or at trial. Moreover, it is unclear whether the records were relevant to the probable cause hearing. Neither the language nor the history of G. L. c. 277, § 68, suggests that a prosecutor may use an evidentiary hearing intended for one purpose to subpoena records for another, unrelated purpose. We conclude that such use of a subpoena would be improper.24
Second, the Commonwealth suggests that a reference we made in Lampron to G. L. c. 277, § 68, shows that the Commonwealth may use G. L. c. 277, § 68, instead of mie 17 (a) (2), to obtain third-party records before trial. The Commonwealth is not correct. In Lampron, the Commonwealth argued that defense counsel’s affidavit filed in support of a motion to subpoena documentary evidence was flawed because it included facts not within counsel’s personal knowledge. Lampron, 441 Mass. at 270. In explaining that we were “disinclined to give a hypertechnical reading” to the requirement that such an affidavit be made on personal knowledge, see Mass. R. Crim. P. 13 (a) (2), as appearing in 442 Mass. 1516 (2004), we referred to a prosecutor’s authority under G. L. c. 277, § 68, to issue a subpoena under his or her own signature, with no required showing of personal or any other knowledge on the prosecutor’s part. See Lampron, supra at 270-271. The reference was intended only to illustrate the point that, in view of a prosecutor’s ability to issue a records subpoena (for trial or an evidentiary hearing) with no showing of personal knowledge, it would be inappropriate to require a far more onerous showing from the defendant under rule 17; we did not mean to suggest that a prosecutor may obtain third-party records before trial under G. L. c. 277, § 68. In fact, in other cases we have said it would be improper for a prosecutor to do so. See Commonwealth v. Mitchell, 444 Mass. at 798 n.17 (“it would be unethical for the Commonwealth to use [its] statutory authority [185]*185[G. L. c. 277, § 68,] for any purpose other than to present a witness or evidence to a court or grand jury”). See also Commonwealth v. Cote, 407 Mass. 827, 832 (1990); Commonwealth v. Smallwood, 379 Mass. 878, 887 (1980); Commonwealth v. Liebman, 379 Mass. 671, 676-677 (1980). As we have explained above, rule 17 (a) (2), and Lampron, not G. L. c. 277, § 68, provide the proper mechanism to subpoena third-party records before trial.
Third, the Commonwealth argues that, were it required to comply with Lampron, it should only have to do so where the records sought are privileged or confidential, and the defendant’s telephone calls in this case were neither. Again, we disagree. Although Lampron involved a defendant’s attempt to subpoena statutorily privileged records, we have applied the Lampron standard to requests for other types of records, not all of which were privileged or necessarily confidential. See Commonwealth v. Matis, 446 Mass. 632, 633, 635 (2006) (standard applied to request to inspect, measure, and photograph interior of complainant’s home); Commonwealth v. Reed, 444 Mass. 803, 807-808 (2005) (standard applied to request for medical records concerning complainant’s pelvic examination); Commonwealth v. Lam, 444 Mass. at 231 (standard applied to request for elementary and middle school attendance records). Moreover, the Nixon standard has been applied in Federal courts to both prosecutors’ and defendants’ efforts to seek a wide array of records, not all of which were necessarily confidential. See, e.g., United States v. Smith, 135 F.3d 963, 972-973 (5th Cir. 1998) (government sought from television station nonconfidential videotape recording of interview of defendant); United States v. Beckford, 964 F. Supp. 1010, 1031 (E.D. Va. 1997) (defendants sought, among other things, records from State and Federal correctional facilities concerning defendants themselves); United States v. King, 164 F.R.D. 542, 545-546 (D. Kan. 1996) (defendant sought patrol logs of security company hired to patrol bank where defendant accused of robbing automatic teller machine, as well as personnel records of bank employees); United States v. Walters, 558 F. Supp. 726, 727-728 (D. Md. 1980) (government sought from telephone companies records of telephone calls defendant made to his mother and former employer).25
[186]*186In arguing that it should not have to comply with Lampron when seeking nonprivileged and nonconfidential records before trial, the Commonwealth mentions as examples of such records “medical records of persons treated after a motor vehicle collision; school attendance records of a child rape victim; or bank or credit records of a larceny victim.” But, as shown above, when comparable sorts of records are sought by defendants, courts have required the defendants to comply with Lampron. We reject the Commonwealth’s suggestion that its duty to investigate crimes absolves it of having to comply with the same procedures as defendants, particularly given the Commonwealth’s formidable investigatory tools, including its grand jury subpoena power. See note 25, supra26 The procedures required by rule 17 seem especially appropriate in a case like this one, where the information sought — recordings of the defendant’s telephone conversations — are at least arguably confidential in some sense, whether entitled to constitutional protection or not.
This result is consistent with Federal decisions upholding claims that prosecutors, without first obtaining judicial approval under [187]*187Fed. R. Crim. P. 17 (c) and Nixon, had improperly issued pretrial subpoenas to correctional facilities seeking recorded telephone conversations of detainees. See United States vs. Eye, U.S. Dist. Ct., No. 05-00344-01-CR-ODS (W.D. Mo. April 15, 2008) (government misused rule 17 [c] subpoena without seeking court order where it issued subpoena to correctional facility for recordings of defendant’s telephone calls with return date of first day of trial, “knowing full well,” based on experience with prison, recordings would be — and were — voluntarily mailed to prosecutor’s office before trial)27; United States v. Noriega, 764 F. Supp. at 1492-1494 (without seeking prior judicial approval, government improperly issued rule 17 [c] subpoenas to correctional facility seeking recordings of telephone calls of detainee where subpoena’s return dates corresponded with no court proceedings; need for judicial approval should have been “manifest” given “coinciding interests of prosecutors and prison authorities,” rendering subpoenas “mere formalities”; “a prison recording policy premised on legitimate security needs was transformed into freewheeling and open-ended discovery for the prosecution”). These cases support our conclusion that the Commonwealth should have sought prior judicial approval under rule 17 (a) (2) and Lampron to issue the subpoena here.28
We therefore agree with the motion judge that the subpoena [188]*188in this case issued improperly. We do not agree, however, that the circumstances warrant suppression. In allowing the defendant’s motion to suppress, the judge, finding that the Commonwealth acted in good faith, ruled only that the manner in which the Commonwealth issued the subpoena was defective; he made no ruling on whether the Commonwealth’s obtaining the recordings violated any constitutional right of the defendant’s for which evidentiary exclusion of the recordings might be appropriate. See Commonwealth v. Lora, 451 Mass. 425, 438-439 (2008) (exclusionary rule typically reserved for cases involving constitutional violations). Nor did the defendant voice any objection to the motion judge’s deferment of the constitutional issues to a later time.
The defendant has not claimed prejudice from the Commonwealth’s procedural misstep in failing to comply with rule 17 (a) (2) and Lampron. He was provided copies of the subpoenaed recordings early in the proceedings, and the Commonwealth has narrowed its interest in the defendant’s calls to a circumscribed period, from January 19 to March 6, 2007. See Commonwealth v. Smallwood, 379 Mass. at 888, quoting Commonwealth v. Hanger, 377 Mass. 503, 509 (1979) (no prejudice where, despite prosecutor’s interview of witness through misuse of G. L. c. 277, § 68, subpoena, existence of interview and statements of witness revealed to defendant “sufficiently in advance of trial to permit investigation”). See also United States vs. Eye, supra (no prejudice where defendant claimed no prejudice; was given copies of recordings shortly after government received them; and was in no worse position than if government had obtained recordings properly under rule 17 [c]); United States v. Noriega, 764 F. Supp. at 1494 (no prejudice where government provided recordings to defendant, “thereby precluding the ‘trial by ambush’ which results when a defendant’s statements hidden from discovery are suddenly used against him at trial”).
[189]*189We therefore conclude that the Commonwealth’s failure to comply with G. L. c. 277, § 68, and rule 17 (a) (2), does not itself warrant suppression of the defendant’s recorded telephone conversations. As we noted at the outset, however, the defendant’s motion to suppress raised a claim that suppression of this evidence was required because turning the records over to the prosecution without any showing of probable cause violated various of his constitutional rights. The judge did not reach these claims, but the defendant is now entitled to have them considered.
We remand the case to the county court for entry of an order vacating the Superior Court order allowing the motion to suppress and remanding the case for further proceedings consistent with this opinion.
So ordered.