(dissenting, with whom Ireland, C.J., joins). I agree with the court that the defendant was not in custody during the interrogation and therefore was not entitled to the warnings required under Miranda v. Arizona, 384 U.S. 436 (1966) (Miranda). I also agree that the sole issue in this case is whether the Commonwealth has met its burden of proving beyond a reasonable doubt that the defendant’s statements to Trooper Peter Cummings and the Chelmsford fire investigator that Trooper Cummings assured the defendant were “off the record” were *213made voluntarily, and that the voluntariness of these “off the record” statements is based on the totality of the circumstances. I further agree that the record suggests that the defendant was intelligent, that he was not under the influence of drugs or alcohol at the time of the interview, and that the only aspect of the interview that raises an issue of voluntariness is Trooper Cummings’s assurance to the defendant that certain statements were “off the record.”
I respectfully dissent because I conclude that, where a law enforcement officer promises a suspect that what he says will be off the record, and the suspect speaks to the police in reliance on that promise, the failure to keep that promise is so significant a factor in the totality of the circumstances that it alone suffices to render such statements involuntary. Because the off-the-record statements that were not suppressed were important evidence of the defendant’s motive to commit the arson, I conclude that the judge’s error in denying the motion to suppress these statements was not harmless beyond a reasonable doubt, and that the judgment of conviction should be reversed and the case remanded for a new trial.
The phrase, “off the record,” has two meanings: “not recorded as official evidence of a proceeding, such as a trial or deposition,” Black’s Law Dictionary 1196 (9th ed. 2009), and “[c]onfidential; not for publication or attribution.” The Dictionary of American Slang 398 (3d ed. 1995). See Black’s Law Dictionary, supra (“not intended for quotation or attribution”); American Heritage Dictionary of the English Language 1221 (4th ed. 2006) (“[njot for publication or attribution”). Under the first meaning, a statement that is “off the record” would not be admitted in evidence at a criminal trial. Under the second meaning, a statement that is “off the record” may not be quoted or attributed to the declarant, but may be used by the listener to provide background or context to other information the listener has learned, or to develop new information, such as by providing leads that a reporter or investigator may follow up. Under either meaning, an investigator who agrees to accept information from a suspect “off the record” agrees not to testify at trial as to what the declarant said off the record. Here, Trooper Cummings did just that, and the motion judge concluded that *214“the defendant was likely misled concerning the ultimate use against him” of the statements he made “off the record.”1
In Commonwealth v. DiGiambattista, 442 Mass. 423, 432 (2004), we recognized that police “trickery” during an interrogation may cast doubt on the voluntariness of a suspect’s statement. The trickery at issue in that case was the use of a ruse to make the suspect believe that the police had more evidence than they did. Id. at 427 (police suggested to suspect that they possessed videotape surveillance recording of area around residence on day it burned). We concluded that “where the use of a false statement [by the police] is the only factor pointing in the direction of involuntariness, it will not ordinarily result in suppression, but ... if the circumstances contain additional indicia suggesting involuntariness, suppression will be required” (emphasis in original). Id. at 433, and cases cited. See United States v. Lopez, 437 F.3d 1059, 1065 (10th Cir. 2006), quoting Clanton v. Cooper, 129 F.3d 1147, 1158 (10th Cir. 1997) (“It is well-settled that a confession is not considered coerced merely because the police misrepresented to a suspect the strength of the evidence against him”).
But there are at least three other forms of police trickery that more severely undermine voluntariness: false promises of leniency in return for a suspect’s statement, false representations regarding the defendant’s right to defend himself at trial, and false promises that the statement will not be used against the suspect. As to false promises of leniency, we have said:
“An officer may suggest broadly that it would be ‘better’ for a suspect to tell the truth, may indicate that the person’s cooperation would be brought to the attention of the public officials or others involved, or may state in general terms that cooperation has been considered favorably by the courts in the past. What is prohibited, if a confession is to stand, is an assurance, express or implied, that it will aid the defense or result in a lesser sentence.” (Footnotes omitted.)
Commonwealth v. Meehan, 377 Mass. 552, 564 (1979), cert. *215dismissed, 445 U.S. 39 (1980). We have more recently reaffirmed that, where this line is crossed, the suspect’s statements will be found involuntary. See Commonwealth v. Novo, 442 Mass. 262, 269 (2004) (because other grounds tainted defendant’s confession, “we need not determine whether any implied assurance of leniency made to [the defendant] crossed the line we set out in Commonwealth v. Meehan, [supra]”); Commonwealth v. Raymond, 424 Mass. 382, 395 (1997) (“officer suggesting that the defendant should tell ‘his side of the story’ fell short of the assurance prohibited in Meehan”). See also United States v. Lopez, supra at 1064-1065 (confession involuntary where Federal agent promised that defendant will spend fifty-four fewer years in prison if he confessed to killing victim by mistake).
As to false representations regarding the defendant’s right to defend himself at trial, where the interrogating police officer told the defendant that this was his “only opportunity” to offer an explanation for why he hit the victim and “[i]f you don’t give us a reason ... a jury’s never going to hear a reason,” we declared that the misrepresentation of the defendant’s right to defend himself at trial “is a particularly egregious intrusion” on a fundamental right that “is different in degree from false statements regarding the strength or existence of incriminating evidence.” Commonwealth v. Novo, supra at 268, 269. We concluded that this type of misrepresentation “casts substantial doubt on the voluntariness of a subsequent confession and on the integrity of the interrogation process leading up to it . . . [that] would be extremely difficult for the Commonwealth to overcome in any case, and it has not done so here.” Id. at 269.
The misrepresentation at issue here — false promises that a statement will not be used against the suspect — casts as much substantial doubt on the voluntariness of the statement as false promises of leniency and false representations regarding the defendant’s right to defend himself at trial. Where the police falsely assure a suspect that his statement will aid the defense or result in a lesser sentence, the suspect is misled to believe that he will help himself by making a statement to the police. Where the police falsely represent a suspect’s right to defend himself at trial, the suspect is misled to believe that he must *216speak now or lose the opportunity to offer an explanation as to what happened or the reasons underlying his actions. Where the police falsely promise that a suspect’s statement will not be used against him, the suspect is misled to believe that what he says to the police will not be repeated before a grand jury or at trial. “[G]iven the uniquely influential nature of a promise from a law enforcement official not to use a suspect’s inculpatory statement, such a promise may be the most significant factor in assessing the voluntariness of an accused’s confession in light of the totality of the circumstances.” United States v. Walton, 10 F.3d 1024, 1030 (3d Cir. 1993).2
A suspect’s understanding that anything he says can and will be used against him is so fundamental that where a suspect is in custody, the United States Supreme Court requires that a suspect be so advised as part of the Miranda warnings. Miranda, supra at 469. The police owe no obligation to furnish this warning to a suspect, like the defendant, who is not in custody when interrogated, but there is a world of difference between the police remaining silent as to whether a suspect’s statement will be used against him and the police affirmatively telling a suspect *217that his statement will not be used against him. “It is only through an awareness of these consequences [that anything said can and will be used against a suspect] that there can be any assurance of real understanding and intelligent exercise of the privilege [against self-incrimination]. ’ ’ Id. Consequently, where a suspect is assured by an interrogating law enforcement officer that his statement will not be used against him, a statement arising from such an assurance is involuntary. See Streetman v. Lynaugh, 812 F.2d 950, 957 (5th Cir. 1987) (“[C]ertain promises, if not kept, are so attractive that they render a resulting confession involuntary. ... A promise of immediate release or that any statement will not be used against the accused is such a promise”). See also United States v. Lall, 607 F.3d 1277, 1285-1288 (11th Cir. 2010); Hopkins v. Cockrell, 325 F.3d 579, 584-585 (5th Cir.), cert. denied sub nom. Hopkins v. Dretke, 540 U.S. 968 (2003); Henry v. Kernan, 197 F.3d 1021, 1027-1028 (9th Cir. 1999), cert. denied, 528 U.S. 1198 (2000); United States v. Swint, 15 F.3d 286, 289-292 (3d Cir. 1994); United States v. Walton, supra at 1029-1032; United States v. Conley, 859 F. Supp. 830, 836 (W.D. Pa. 1994), aff’d, 92 F.3d 157 (3d Cir. 1996), cert. denied, 520 U.S. 1115 (1997).
In United States v. Lall, supra at 1287, a detective “explicitly assured [the defendant] that anything he said would not be used to prosecute him” and there was “ample record evidence to support a finding that [the detective’s] promise was deceptive.” The prosecution argued that the assurances by a State law enforcement officer did not bar the use of the resulting confession in a Federal prosecution, but the United States Court of Appeals for the Eleventh Circuit rejected this argument, concluding that “the only plausible interpretation of [the detective’s] representations, semantic technicalities aside, was that the information [the defendant] provided would not be used against him by [the detective] or anyone else.” Id. Even though the defendant had received Miranda warnings advising him that everything he said can and will be used against him, the court held that the detective’s statements “were sufficient to render [the defendant’s] confession involuntary and to undermine completely the prophylactic effect of the Miranda warnings [the detective] previously administered.” Id.
*218In Hopkins v. Cockrell, supra at 584, the law enforcement officer “assured [the defendant] that their conversation was confidential, telling [the defendant], ‘This is for me and you. This is for me. Okay. This ain’t for nobody else.’ ” The United States Court of Appeals for the Fifth Circuit held that the defendant’s confession was involuntary. Id. at 585. The court declared, “An officer cannot read the defendant his Miranda warnings and then turn around and tell him that despite those warnings, what the defendant tells the officer will be confidential and still use the resultant confession against the defendant.” Id.3
In Henry v. Keman, supra at 1027, the defendant, who was in custody, invoked his right to counsel, but the detective continued to question him, in violation of the Miranda decision. After the defendant, who continued to answer the detective’s questions, asked whether he was “supposed to keep talking without an attorney,” the detective told him, “Listen, what you tell us we can’t use against you right now. . . . We’d just would like to know.” Id. The United States Court of Appeals for the Ninth Circuit declared that the detective’s “misleading comments were intended to convey the impression that anything said by the defendant would not be used against him for any purposes.” Id. at 1027-1028. The court held that the statements the defendant made after he invoked his right to counsel were involuntary, and therefore could not be used for impeachment purposes. Id. at 1029.
In United States v. Swint, supra at 287, the defendant accepted an invitation to make an “off-the-record proffer regarding the cooperation he could provide in exchange for a negotiated plea on the outstanding charges against him.” After the defendant denied any wrongdoing, Federal agents joined the State and local law enforcement officers in the interview room, and urged the defendant to cooperate, telling him they had a warrant for his arrest on Federal drug charges with a ten-year mandatory sentence. Id. at 288. The defendant conferred with his attorney, agreed to cooperate with the Federal agents, and *219made inculpatory statements. Id. The United States Court of Appeals for the Third Circuit concluded that the statements were involuntary, noting that the statements were made in an “informal, off-the-record proffer,” that neither the defendant nor his attorney were informed that Federal agents would be at the proffer meeting or that Federal charges would be discussed, and that “neither the state nor federal agents clearly informed [the defendant] or his attorney that [the defendant’s] statements to the [Federal] agents would not be off-the-record.” Id. at 290.
In United States v. Walton, 10 F.3d 1024, 1027 (3d Cir. 1993), during a noncustodial meeting between the defendant and a Federal agent on a park bench, the Federal agent told the defendant, “I’ve known you for a long time. If you want, you can tell us what happened off the cuff.” The defendant then made admissions that the prosecution used against him at trial. The United States Court of Appeals for the Third Circuit concluded that the confession was involuntary, noting that “there was no reason for [the defendant] to disbelieve [the Federal agent] that nothing he said would be used against him.” Id. at 1030. “A person without prior exposure to the criminal justice system, even one with [the defendant’s] intelligence and education, could easily be taken in and induced to speak under these circumstances.” Id.4 See United States v. Conley, 859 F. Supp. 830, 833 (W.D. Pa. 1994) (defendant’s statements held involuntary where Federal agent assured him that what he said was “off the record”). In each case, the court determined the voluntariness of the defendant’s statement under the totality of the circumstances, but the circumstance that controlled the finding of voluntariness was the false assurance that the statement would not be used against the defendant.
*220In the only case I have found where an appellate court did not hold a defendant’s statements involuntary after an interrogating officer assured the defendant that his statements would not be used against him, United States v. Flemmi, 225 F.3d 78, 82 (1st Cir. 2000), cert. denied, 531 U.S. 1170 (2001), the motion judge found that Federal agents had promised the defendant both use and derivative use immunity when he worked as their informant. The immunity that was promised not only protected the defendant from the admission in evidence of statements he made to Federal agents while serving as an informant, but also protected him from any derivative use of these statements, and from any use, direct or derivative, of all conversations intercepted during the course of court-authorized electronic surveillance at three separate locations, even conversations in which the defendant did not participate. Id. at 82-83. The United States Court of Appeals for the First Circuit held that these broad promises of use and derivative use immunity were unenforceable because Federal agents lacked the authority to make them. Id. at 91. The court briefly addressed the defendant’s claim of involuntariness, and rejected it because there was no evidence of any threats, retaliation, violence, or “consciously misleading conduct on the part of the [Federal] agents,” and because the defendant was neither incarcerated nor under investigation at the time of the asserted promise, and “enjoyed a friendly — even social — relationship” with the Federal agents. Id. at 92. In short, the promises made to Flemmi were extraordinarily broad claims of immunity that exceeded the authority of the Federal agents and these promises were made to him as an informant, not as a suspect during interrogation. Therefore, the circumstances in the Flemmi case are far different from those in the other cases cited. Even the Flemmi court appeared to recognize that its case was distinguishable because it cited with approval both United States v. Swint, 15 F.3d 286, 290-291 (3d Cir. 1994), and United States v. Walton, supra at 1028. See United States v. Flemmi, supra.
The court’s opinion recognizes that assuring a suspect that his statements will be “off the record” and then repeating those statements at trial is “a tactic that should be avoided,” ante at 212, but it fails to acknowledge what virtually every court con*221fronting a comparable assurance has recognized — that statements induced by such assurances are involuntary. I conclude that the statements the defendant made “off the record” should be suppressed, and the conviction should be reversed because the admission of these statements was not harmless beyond a reasonable doubt.51 respectfully dissent.
At trial, Trooper Peter Cummings admitted that he had lied to the defendant when he assured him that what he said would be “off the record.”
Judge Richard A. Posner has written that “the courts’ actual as distinct from articulated standard [for involuntariness] is to ask whether the government has made it impossible for the defendant to make a rational choice as to whether to confess — has made it in other words impossible for him to weigh the pros and cons of confessing” (emphasis in original). United States v. Rutledge, 900 F.2d 1127, 1129 (7th Cir.), cert, denied, 498 U.S. 875 (1990). He explained:
“If the officers, fully intending to use anything [the defendant] said against him, had said to him, ‘Tell us all you know about the drug trade, and we promise you that nothing you tell us will be used against you,’ then he would have a strong argument that any ensuing confession had been extracted by fraud and was involuntary. . . . For in our hypothetical case the officers would have deflected [the defendant] from weighing the pros and cons of confessing and going in the direction that the balance leaned. Alternatively, [the defendant] could in our hypothetical case hold the government to its promise, and could do so whether or not the promise was fraudulent.”
Id. at 1130. See United States v. Male Juvenile (95-CR-1074), 121 F.3d 34, 41 (2d Cir. 1997) (question of voluntariness “is whether the government agents somehow misled defendant into believing that he could choose to speak without consequences, thus denying him any rational choice of whether to waive his rights and confess”).
Although the court concluded that the confession was involuntary, it did not vacate the defendant’s conviction, finding the error harmless. Hopkins v. Cockrell, 325 F.3d 579, 585 (5th Cir.), cert, denied sub nom. Hopkins v. Dretke, 540 U.S. 968 (2003).
The court seeks to distinguish the holding in United States v Walton, 10 F.3d 1024 (3d Cir. 1993), from the instant case by noting that the Federal agent in the Walton case had a prior relationship with the suspect, while Trooper Cummings had no prior relationship with the defendant. See ante at 210 n.7. That prior relationship was relevant only because it strengthened the inference that the defendant believed the Federal agent’s assurance that he would not use what he said against him. United States v. Walton, supra at 1030. Here, where Trooper Cummings expressly agreed that part of what the defendant said would be off the record and even negotiated with the defendant to place certain off-the-record statements “on the record,” there is no reason for the defendant to have disbelieved the trooper’s assurance.
At a retrial, the prosecution would be able to offer in evidence all of the defendant’s statements to Trooper Cummings and the fire investigator except those made off the record during the interview, including all the information that Trooper Cummings included in his report of the interview.