Botsford, J.
The defendant appeals from his conviction of murder in the first degree. His primary argument on appeal is that his motion to suppress a secretly recorded conversation between him and an informant working with the police was erroneously denied, that evidence of the conversation should have been excluded at trial, and that his conviction must be reversed as a result.1 We agree and reverse the defendant’s conviction.
Background. 1. Electronically recorded conversation. Dana Haywood was shot and killed on July 4, 2005, in the Monte Park neighborhood of New Bedford. Over three years later, in February of 2009, an assistant district attorney in the Bristol district received a letter from Rico Almeida, who was then sharing a cell with the defendant in the Bristol County house of correction. Al-meida wrote that the defendant had been one of the participants in the shooting death of Haywood on July 4, 2005, that the defendant had told Almeida “how they did it, where, and when,” and that Almeida would be able to arrange for the defendant to repeat this admission to the shooting of the victim. Almeida offered to wear a concealed recording device and record the proposed conversation. In response to the letter, the Commonwealth submitted an affidavit of Trooper Anthony Spencer of the State police to a judge in the Superior Court, and obtained a search warrant authorizing the electronic recording of conversations [135]*135between the cooperating witness (i.e., Almeida) and the defendant.2
In an affidavit dated March 2, 2009, Spencer begins by reciting the following information about police officers’ prior dealings with Almeida in a homicide investigation involving William Payne. Payne was shot and killed on February 3, 2008, in New Bedford. During the investigation of the Payne homicide, in October of 2008, State police Trooper Paul Dockrey had interviewed Almeida, who at the time was being held in custody at the Bristol County house of correction. Dockrey learned from Al-meida that the latter had information about Payne’s murder from two “gang business meetings” where he and his friends discussed how to handle their friend Payne’s homicide. In particular, Almeida learned specific details about “how the Payne homicide went down.” Based on these facts, Dockrey sought and obtained a search warrant that authorized Almeida to record telephone conversations electronically with the suspects in the Payne murder, and Almeida was released on bail from custody in order to do so. Once he was released, however, Almeida failed to secure the recordings.
Spencer’s affidavit then turns to the homicide investigation relating to Dana Haywood, the victim in this case. It states that in a letter dated February 14, 2009, and sent to an assistant district attorney, Almeida provided information about the July 4, 2005, homicide, and indicated he was willing to assist law enforcement in the investigation and to “wear a ‘wire’ for this purpose.” Spencer’s affidavit then states as follows:
“I spoke with Det. Lt. Scott Sylvia, New Bedford Police Major Crimes Division, and he informed me that John Bur-gos is a member of the United Front gang. He has been associated with the gang for approximately 12 years. According to Det. Lt. Sylvia the United Front gang is a group of individuals that operate in and around the United Front Homes located adjacent to Chancery and Kempton Streets. The members are known to be heavily involved in the distribution of illegal narcotics. The members are also known to commit violent crimes including possession of firearms [136]*136and multiple shootings. Mr. Burgos himself was also a target of a shooting on May 21, 2006 along with Justin Barry who was murdered in the shooting. This shooting was perpetrated by rival Monte Park members including David DePina. Mr. DePina is presently awaiting trial in the fatal shooting of Barry and the shooting of Mr. Burgos.
“Tpr. Ann Marie Robertson, Cold Case Unit Mass. State Police, advises me that Dana Haywood was a known member of the Monte Park Gang at the time of his death. Monte [ ] Park Gang is a group of individuals that are known to distribute illegal narcotics by Monte[ ] Park on Acushnet Avenue in the city of New Bedford. The gang members are also known to commit violent crimes including illegal possession of firearms and multiple shootings. Tpr. Robertson informs me that investigators believe that Dana Haywood’s murder is suspected to be in retaliation for the fatal shooting of Cecil Lopes which occurred on October 31, 2004. The Cecil Lopes murder took place at the United Front Homes on Chancery Street in the city of New Bedford. The Cecil Lopes murder involved a shooting directly outside a residence in the United Front Housing complex. Tpr. Robertson informs me that Mr. Haywood was shot one block from the Monte Park Housing complex on Russell Street in the city of New Bedford. Tpr. Robertson further advises me that eyewitnesses to Mr. Haywood’s shooting saw 3 young black males, at least 2 of who [sic] were shooting. The 3 males fled from Mr. Haywood’s body to an awaiting vehicle.”
Following these two paragraphs, the affidavit describes the contents of Almeida’s February 14, 2009, letter to the assistant district attorney:
“Almeida stated in his letter that his cell mate, John Burgos [the defendant] was one of the shooters who killed Dana Haywood [the victim] on July 4, 2005. Almeida also states John Burgos told him why, where and when they did it. Almeida believes he can get Burgos to make those statements again. Almeida requests that this investigation be expedited due to the fact that Burgos will be released soon.”
The affidavit then describes the manner in which the electronic recording by Almeida would be set up.
[137]*137Based on Spencer’s affidavit, the Superior Court judge issued the requested search warrant. Police officers then provided Almeida with an electronic recording device that Almeida hid on his person and used to secretly record a conversation with the defendant in their jail cell on March 3, 2009. During the conversation, which lasted over sixty minutes, the defendant admitted to being one of the shooters involved in killing the victim on July 4, 2005, and described the actual shooting incident in some detail, as well as his attitude toward it.
Following the defendant’s indictment on charges of murder and unlawful possession of a firearm, he filed a motion to suppress the electronically recorded statements. He argued that the recording was obtained in violation of the wiretap statute, G. L. c. 272, § 99, because the Commonwealth had not made the requisite showing that the recording would lead to evidence about a “designated offense” committed “in connection with organized crime.” See G. L. c. 272, § 99 B 4, 7. The defendant also argued that the search warrant had been issued without probable cause. In opposition to the motion, the Commonwealth did not offer any evidence other than Trooper Spencer’s affidavit that had previously been submitted in support of the Commonwealth’s search warrant application.
A second Superior Court judge held a nonevidentiary hearing on the defendant’s suppression motion, and thereafter denied it. The judge concluded in substance that Spencer’s affidavit articulated sufficient facts to indicate that the victim’s murder was committed in connection with organized crime because the facts showed the murder was “gang related.”3
The defendant was tried and convicted of murder in the first degree in November, 2010.4 He filed a timely notice of appeal and thereafter filed a motion for a new trial that raised a claim of ineffective assistance of trial counsel. The motion was remanded to the Superior Court. After receiving memoranda from the parties, the trial judge denied the motion in an explanatory order. The defendant filed a timely appeal from the denial. We have consolidated for review the defendant’s appeal from his conviction and from the denial of his motion for a new trial.
[138]*1382. Evidence at trial. We summarize briefly what the jury could have found based on the trial evidence. On October 31, 2004, some nine months before the victim was killed on July 4, 2005, Cecil Lopes, a resident of the United Front housing development in New Bedford, had been killed. In November, 2004, the defendant, who also lived in the United Front development, had made a telephone call to his brother.5 In this conversation, he and his brother had talked about how Lopes’s photograph was in the newspaper, and the defendant had stated that he had put the image from the newspaper on his wall. They also had discussed that someone named “Aceon” was responsible for the killing. Aceon was known to be associated with the Monte Park area of New Bedford. The Commonwealth’s theory at trial was that the defendant and his friend William Payne killed the victim in retaliation for Lopes’s murder.
At the scene of the shooting resulting in the victim’s death, police recovered a blue baseball cap and some bullet shell casings. A bystander had seen three individuals at the scene, all of whom were wearing white T-shirts. Later that night, the defendant and Payne were at the home of Payne’s grandfather who observed the defendant to be laughing and behaving differently than he usually did.
Almeida, who had entered into a cooperation agreement with the Commonwealth, was a witness at trial. He testified about, among other subjects, his March, 2009, electronically recorded conversation with the defendant.6 A recording of the recorded conversation was then played for the jury and entered into evidence as an exhibit. In that conversation, the defendant agreed with Almeida’s assertion that he and Payne shot the victim, described the shooting as “executionist style,” and made statements suggesting a lack of any feelings of guilt or remorse. He also indicated that he had been wearing a white T-shirt at the time of the shooting, and that the victim had been killed in retaliation for the death of Cecil Lopes.
[139]*139Deoxyribonucleic acid (DNA) testing was performed on the baseball cap found at the scene of the shooting. It revealed that the defendant was the source of the major profile taken from the swabbings and scrapings of the baseball cap, and that the victim was excluded from that profile. The shell casings found at the scene were compared to a shell casing found three months later in a car driven by Payne. The State police trooper who did the comparison opined that the casings were fired from the same unknown weapon.
Discussion. 1. Motion to suppress recorded statement. The defendant contends that the secret recording of his conversation with Almeida should have been suppressed because the Commonwealth obtained this evidence in violation of the wiretap statute, G. L. c. 272, § 99. He argues principally that the Commonwealth failed to show that the recording was made during an investigation of a designated offense committed “in connection with organized crime,” as that statute requires. See G. L. c. 272, § 99 B 4, 7.
The Commonwealth’s wiretap statute generally prohibits the secret recording of oral communications, see G. L. c. 272, § 99 C 1, but also contains some narrow exceptions to this prohibition. One of those exceptions, described in § 99 B 4, is for a one-party consent recording, where the person who is conducting the surreptitious recording “is an investigative or law enforcement officer investigating a ‘designated offense,’ and that officer is either (1) a party to the communication, or (2) has advance authorization from a party to the communication to intercept the conversation.” Commonwealth v. Hearns, 467 Mass. 707, 714 (2014), quoting Commonwealth v. Tavares, 459 Mass. 289, 297 (2011).7 See Commonwealth v. Thorpe, 384 Mass. 271, 275-276 (1981), [140]*140cert, denied, 454 U.S. 1147 (1982).
The Commonwealth from the outset of this case has characterized the recording at issue here as fitting within the one-party consent exception set out in G. L. c. 272, § 99 B 4. There is no dispute that most of the requirements of that exception are met here: the recording was carried out by law enforcement officers investigating the victim’s murder; murder is one of the crimes listed in the definition of “designated offense” in § 99 B 7; and Almeida, one of the parties to the recorded conversation, had authorized (in fact, requested) the officers in advance to conduct the recording. But, as the defendant contends, for the victim’s murder actually to qualify as a “designated offense” within the meaning of § 99 B 7, it must have been a murder committed “in connection with organized crime” — that is, it was necessary for the Commonwealth “to show that the decision to intercept was made on the basis of a reasonable suspicion that interception would disclose or lead to evidence of a designated offense in connection with organized crime.” Thorpe, 384 Mass, at 281. In this context, the term “organized crime” means “a continuing conspiracy among highly organized and disciplined groups to engage in supplying illegal goods and services.” G. L. c. 272, § 99 A. See Thorpe, supra at 277.
To show a nexus to organized crime, there must be “some evidence of an ongoing illegal business operation.” Tavares, 459 Mass. at 300, quoting Commonwealth v. Long, 454 Mass. 542, 556 (2009). The Commonwealth also must demonstrate a “high degree of discipline and organization” among the suspected members of the criminal enterprise. Tavares, supra at 300, quoting Commonwealth v. D’Amour, 428 Mass. 725, 737 (1999). However, facts suggesting “coordination of efforts among cohorts standing alone is insufficient. . . . ‘For a conspiracy to commit an offense enumerated in G. L. c. 272, § 99 B 7, to rise to the level of organized crime, there must, at the very least, be an organized plan from which one reasonably may infer the existence of an ongoing criminal operation.’ ” Tavares, supra at 301, quoting Long, supra at 557. Finally, the Commonwealth must show that the designated offense was committed to promote “the supply of ‘illegal goods and services’ or the furtherance of an ‘ongoing criminal business operation.’ ” Tavares, supra at 301, quoting G. L. c. 272, § 99A.
[141]*141In recent years, this court has decided a number of cases involving the one-party consent exception under our wiretap statute, and the facts of those cases offer useful comparisons here. In Tavares, the Commonwealth failed to show a nexus to organized crime when requesting a wiretap in an investigation of a murder resulting from a drive-by shooting. The facts contained in a State trooper’s supporting affidavit revealed that the defendant and the other men suspected of participating in the crime were known to carry guns and commit violent crimes, and that the defendant had purchased a gun from a fellow group member. Tavares, 459 Mass. at 299. The facts also indicated that the defendant and the other men borrowed a car in advance, met at a central location before the shooting, and returned to hide the guns at the same site afterwards, suggesting some coordination and that there was some degree of a hierarchy within the group. Id. at 291, 299. However, we concluded that taken together, the facts in Tavares did not support a connection to organized crime because there was no information beyond the speculative that the defendant or any other member of his group “was involved in a pecuniary enterprise, such as drug, gun, or contraband trafficking, or promoted some other unifying criminal purpose.” Id. at 301. In addition, the evidence failed to show “other hallmarks of organized crime — discipline, organization, and a continuing nature.” Id. at 302, quoting Long, 454 Mass, at 558. Finally, we observed that there was not a “scintilla of evidence in the [State police trooper’s] affidavit that the designated offense [the drive-by murder of the victim] was committed ‘in connection’ with [an] organized criminal trade.” Tavares, 459 Mass. at 302.
In contrast, in Hearns, 467 Mass, at 710-711, we found a nexus to organized crime based on a detailed affidavit from a police officer outlining his direct knowledge that specific persons in the alleged criminal organization distributed narcotics and possessed firearms. The affidavit also contained information about the use of “mission” assignments “guided and observed by senior members in the organization” as “part of an ongoing ‘feud’ (or war) between turf conscious criminal organizations involved.” Id. at 716. We concluded that “it is reasonable to infer from the information available to the police at the time that the shooting at issue was intended as an act of intimidation directed at [a rival gang] and related to its competing illegal enterprises.” Id. Similarly, in Commonwealth v. Mitchell, 468 Mass. 417,426 (2014), there was clear evidence that the defendant and his associates were in-[142]*142valved in “a drug distribution enterprise.” The defendant himself previously had been arrested in connection with this drug enterprise, along with a fellow associate who a witness confirmed was a known drug dealer. Id. Their enterprise was also highly coordinated, with multiple members taking part in the shooting and several others assisting in hiding the gun and “conspiring to kill a potential witness.” Id. at 427. Facts suggested that the murder was part of a “bitter and violent feud” between two rival organizations. Id. We stated that “[e]yen if the feud were purely personal, an illegal drug distribution business may see the perception of weakness as potentially fatal to an enterprise that wishes to protect its turf against competitors.” Id. This conclusion, however, relied on clear evidence showing that the group was, in fact, operating an organized drug business.
On its facts, this case is much closer to Tavares than to Hearns and Mitchell. In contrast to the latter two cases, the only two relevant paragraphs of Trooper Spencer’s affidavit in this case, quoted supra, set out relatively vague and conclusory “facts” about the existence of two rival gangs operating in different neighborhoods of New Bedford, both of which were involved in selling narcotics. These paragraphs, however, do not describe or even suggest a nexus between the victim’s murder — i.e., the offense being investigated — and the narcotics or any other ongoing business enterprise of either gang. Spencer states in the affidavit that he has learned from other officers that the defendant was a longtime, member of the United Front gang, that the gang is involved “in the distribution of illegal narcotics” inferably near the United Front Homes where the gang operates, that the Monte Park gang of which the victim was a member distributes drugs near Monte Park, and that the victim’s murder was believed to be in retaliation for the earlier murder of Cecil Lopes near the United Front Homes. Nothing in the affidavit, however, indicates that the two gangs were engaged in a turf war or other dispute over drug dealing or any other “business” activities, and nothing connects the murder of the victim or even the defendant to the gangs’ drag dealing operations or any other “business” activity. Moreover, beyond the fact that eyewitnesses saw three individuals at the scene of the murder get into a waiting car, there is no evidence indicating that the trio were members of the United Front gang, much less evidence, that the trio’s actions that night were part of an organized, disciplined plan characteristic of a business enterprise. Contrast Hearns, 467 Mass, at 715-716. A retaliatory killing alone, without a clear link to the [143]*143goals of a criminal enterprise, does not amount to a connection to organized crime. See Long, 454 Mass, at 557-558.
Because Spencer’s affidavit fails to show the requisite connection between the murder being investigated and “organized crime,” the denial of the defendant’s motion to suppress constituted error, and the defendant’s recorded conversation with Almeida should not have been admitted in evidence at trial. The remaining question is the effect of the error. We assume for argument that the substantial likelihood of a miscarriage of justice standard applies.8 Under that standard, “a new trial is called for unless [the reviewing court is] substantially confident that, if an error had not been made, the jury verdict would have been the same.” Commonwealth v. Ruddock, 428 Mass. 288, 292 n.3 (1998).
The recorded conversation between the defendant and Almeida, in which the defendant admitted to having joined with Payne in murdering the victim and described the murder in some detail without indication of remorse or even regret, unquestionably constituted the centerpiece of the Commonwealth’s case. There were no eyewitnesses who identified the defendant as a shooter. The closest evidence in this regard was that three young men in white T-shirts were observed at the scene, and that the defendant had on a white T-shirt that night. The DNA evidence from the blue baseball cap at best places the defendant at the scene of the shooting, but proves nothing more. Although the shell casings recovered by police at the scene of the crime matched the shell casing found in Payne’s car at a later point in time, the actual murder weapon was never found. Reviewing this evidence, we cannot conclude with substantial confidence that the jury would have reached the same verdict had the recorded conversation between the defendant and Almeida been excluded.9 See Ruddock, 428 Mass, at 292 n.3. The defendant’s conviction must be reversed.
[144]*1442. Motion for a new trial. As he did in his motion for a new trial, the defendant argues on appeal that he was deprived of the effective assistance of counsel based on his trial attorney’s failure to move for suppression of all evidence of his conversation with Almeida — both the electronic recording of it as well as testimony of Almeida relating to the contents of the conversation — under the Fifth Amendment to the United States Constitution and art. 12 of the Massachusetts Declaration of Rights. More particularly, the defendant contends that because Almeida was an agent of the police at the time he secretly recorded the conversation with the defendant, and because the recorded conversation took place while the defendant was in custody, the conversation qualified as a “custodial interrogation.” Accordingly, evidence of the conversation was inadmissible because the defendant was not given Miranda warnings before the conversation took place and never waived his right to remain silent. See Miranda v. Arizona, 384 U.S. 436, 444 (1966) (“the prosecution may not use statements ... stemming from custodial interrogation of the defendant unless it demonstrates the use of procedural safeguards effective to secure the privilege against self-incrimination”). By never challenging this evidence on Fifth Amendment and art. 12 grounds, the defendant avers here, his trial attorney’s actions fell “measurably below that which might be expected from an ordinary fallible lawyer” and deprived him of an “otherwise available, substantial ground” of defense. Commonwealth v. Randolph, 438 Mass. 290, 295 n.9 (2002), quoting Commonwealth v. Saferian, 366 Mass. 89, 96 (1974).
“It is not ineffective assistance of counsel when trial counsel declines to file a motion with a minimal chance of success.” Commonwealth v. Conceicao, 388 Mass. 255, 264 (1983). In Illinois v. Perkins, 496 U.S. 292, 297 (1990), the United States [145]*145Supreme Court, focusing on the Fifth Amendment, rejected the argument the defendant makes here. The Court emphasized that Miranda sought to protect or preserve a suspect’s ability to exercise his right against self-incrimination in the “inherently compelling” atmosphere of a police-dominated official interrogation, and concluded that under the Fifth Amendment, incriminating statements made during a voluntary conversation between a suspect who was incarcerated on other charges and his cellmate — an undercover officer posing as an inmate — were not rendered inadmissible because of the absence of Miranda warnings.10 Id. at 296, quoting Miranda, 384 U.S. at 467. The defendant in essence disagrees with the reasoning of the Court’s majority in Perkins, cites to the dissenting opinion of Justice Marshall, and urges us to conclude that under art. 12, the administration of Miranda warnings was required before Almeida, who was in substance a government agent, engaged the defendant in conversation about the circumstances of the victim’s murder. See Perkins, 496 U.S. at 303 (Marshall, J., dissenting). In support of this position, the defendant points out that in the context of Miranda, the court in certain cases has construed art. 12 to afford more protections to suspects of crimes.
In Commonwealth v. Larkin, 429 Mass. 426, 432 (1999), quoting Perkins, 496 U.S. at 297, this court observed that “Miranda warnings are only necessary where one is the subject of ‘custody [146]*146and official interrogation.’ ”“11 We also stated that “[w]hether a suspect was subject to custodial interrogation is a question of Federal constitutional law.” Larkin, supra at 432. Although on occasion we have interpreted art. 12 to afford greater protections to criminal suspects than the Fifth Amendment, see, e.g., Commonwealth v. Mavredakis, 430 Mass. 848, 858 (2000), we are not persuaded that this case presents a ground to do so.12 In other words, considering the purpose of Miranda warnings, we find no good reason to conclude that where an unindicted suspect held in custody on separate charges enters voluntarily into a conversation with a cellmate, art. 12 requires that the suspect receive Miranda warnings before the conversation begins if it turns out that the cellmate was acting as an agent of the police.13
Here, the defendant was not in custody for Miranda purposes during his jail cell conversation with Almeida. Although Almeida was deliberately eliciting information from him, the defendant was not being coerced to answer in any way. Rather, he was [147]*147having a conversation with someone he knew and appeared to consider a friend, and there is nothing to indicate that his statements were anything but voluntary. See Commonwealth v. Tremblay, 460 Mass. 199, 207 (2011). Because there was no basis on which to argue that evidence of the conversation should have been suppressed under the Fifth Amendment or art. 12, the defendant’s trial attorney was not ineffective in failing to raise the claim. The defendant’s motion for a new trial was properly denied.
3. Other issues. Because there may be a new trial, we briefly address the defendant’s two other claims.
First, the defendant asserts that in light of the Commonwealth’s failure to provide sufficient evidence to corroborate his statements made during the electronically recorded conversation with Almeida, his motion for a required finding of not guilty should have been allowed. This argument relies on a misguided application of the corroboration rule, which “requires only that there be some evidence, besides the confession, that the criminal act was committed by someone, that is, that the crime was real and not imaginary.” Commonwealth v. Forde, 392 Mass. 453, 458 (1984). It is not necessary that the corroborating evidence “point to the accused’s identity as the doer of the crime.” Id. In a murder case, the additional evidence “need only tend to show that the alleged victim is dead.” Id. The victim in this case was clearly killed as a result of multiple gunshot wounds. There is therefore no issue whether the crime of murder occurred.14 There was no error in the denial of the defendant’s required finding motion.
The defendant also argues that his motion to suppress evidence of his recorded telephone call with his brother, recorded in 2004 while he was a pretrial detainee in a Bristol County correctional facility, was improperly denied, and evidence of that recorded call should not have been admitted at trial.15 Specifically, he asserts that the subpoena was issued in violation of the procedural requirements of Commonwealth v. Odgren, 455 Mass. 171 (2009). See id. at 184-185 (Commonwealth must obtain judicial approval [148]*148under Mass. R. Crim. R 17 [a] [2], 378 Mass. 885 [1979], before issuing subpoena requiring third party to produce telephone records in advance of trial).
It is true that the procedural requirements spelled out in Odgren were not followed here — Odgren had not been decided when the subpoena was served — but as that case makes clear, suppression of evidence of recorded telephone calls such as the call at issue here is warranted only where the defendant can show that the erroneously issued subpoena caused him prejudice. See id. at 188-189. See also Commonwealth v. Cote, 407 Mass. 827, 833 (1990).
There was no prejudice shown here. The Bristol County district attorney’s office served a subpoena for the defendant’s recorded telephone calls on the Bristol County sheriff on October 5, 2009, without seeking prior judicial approval. On or about October 13, 2009, and in accordance with its policy, the sheriff’s office delivered to the district attorney’s office a copy of the recording of the defendant’s telephone calls made in November, 2004. The defendant received a copy on October 7, 2010. The trial did not begin until a month later, a period of time that allowed the defendant and his counsel to prepare.16’17 See Odgren, 455 Mass, at 188.
Conclusion. The'defendant’s conviction is reversed, the verdict is set aside, and the case is remanded to the Superior Court for a new trial.
So ordered.