ABRAMS, J.

The sole issue on appeal is whether evidence seized in violation of the Fourth Amendment to the Constitution of the United States and art. 14 of the Massachusetts Declaration of Rights should be excluded from a proceeding to revoke probation. We transferred the appeal to this court on our own motion. We conclude, as do a majority of jurisdictions that have considered the issue, that, where the police who unlawfully obtained the evidence neither knew nor had reason to know of the probationary status of the person whose property was seized, the evidence is admissible in a proceeding to revoke probation.

While on probation for prior drug-related convictions in the Westborough Division of the District Court Department, Eva M. Olsen was arraigned on three new drug-related indictments in the Superior Court in Worcester County. A District Court judge held a surrender hearing on the same day the indictments were returned. A police officer testified that drugs and paraphernalia were seized from Olsen's home pursuant to a search warrant. Olsen indicated her intention to file a motion to suppress that evidence in the trial on the new indictments. The judge found that Olsen had violated the terms of her probation but continued the disposition of the matter.

At trial, the judge allowed Olsen's motion to suppress all the evidence. The Commonwealth informed the judge that it would not appeal the suppression and that it had no other evidence with which to convict the defendant. The judge dismissed all three indictments with prejudice. On the same afternoon, Olsen's probation in the District Court was revoked on the basis of the same evidence that the trial judge had suppressed.

Olsen concedes that the majority of jurisdictions, including the Federal courts, that have considered the question have decided that the exclusionary rule does not apply to probation revocation proceedings. The reasons for not excluding the evidence in a probation proceeding based on violation of the Fourth Amendment are the same as those based on the Fifth Amendment. See Commonwealth v. Vincente, ante 278 (1989). Olsen argues, however, that art. 14 may provide broader protection to probationers than the United States Constitution. See Commonwealth v. Fini, 403 Mass. 567, 570 (1988). Olsen urges us to join the minority of States in extending the exclusionary rule to probation revocation proceedings as a matter of State law.

In Federal law and in most jurisdictions, the exclusionary rule does not apply as a matter of course to probation revocation proceedings because the "application of the exclusionary rule is restricted to those areas where its remedial objectives are thought most efficaciously served." See Commonwealth v. Vincente, supra at 280, quoting United States v. Calandra, 414 U.S. 338, 348 (1974). Accord United States v. Bazzano, 712 F.2d 826, 832-833 (3d Cir. 1983), cert. denied sub nom. Mollica v. United States, 465 U.S. 1078 (1984); United States v. Winsett, 518 F.2d 51, 53-54 (9th Cir. 1975); People v. Rafter, 41 Cal.App.3d 557 (1974); Payne v. Robinson, 207 Conn. 565, cert. denied, U.S. (1988) (109 S.Ct. 242 [1988]); People v. Dowery, 62 Ill.2d 200 (1975); Dulin v. State, 169 Ind. App. 211 (1976); State v. Caron, 334 A.2d 495 (Me. 1975); Chase v. State, 309 Md. 224 (1987); State v. Thorsness, 165 Mont. 321 (1974). See also Annot., 77 A.L.R.3d 636 (1977 1988 Supp.). The Supreme Court's dictum in Wong Sun v. United States, 371 U.S. 471, 485 (1963), to the effect that such evidence "shall not be used at all," clearly does not apply to every kind of forum and proceeding under Federal law nor under the law of most States. See United States v. Calandra, supra; Commonwealth v. Vincente, supra; and cases cited, supra.

A probation revocation proceeding is not a criminal trial. Gagnon v. Scarpelli, 411 U.S. 778, 782 (1973). See Morrissey v. Brewer, 408 U.S. 471, 480 (1972). The probationer already has been convicted of a crime at a trial. He or she enjoys "only . . . conditional liberty . . . dependent on observance of special parole restrictions." Morrissey, supra at 480. United States v. Basso, 632 F.2d 1007, 1013 (2d Cir. 1980). Probation is granted with the hope that the probationer will be able to rehabilitate himself or herself under the supervision of the probation officer. "Evidence that a probationer is not complying with the conditions of probation may indicate that he or she has not been rehabilitated and continues to pose a threat to the public." Commonwealth v. Vincente, supra at 280. Accordingly, "the State has an overwhelming interest in being able to return an individual to imprisonment without the burden of a new adversary criminal trial if in fact [the probationer] has failed to abide by the conditions of his [or her probation]." Morrissey, supra at 483.

We weigh this overwhelming State interest in admitting all reliable evidence against the deterrent purpose of the exclusionary rule. Most courts have concluded, and we agree, that a police officer's "zone of primary interest" is in gathering evidence with which to convict a defendant of crime. Bazzano, supra at 832, quoting United States v. Janis, 428 U.S. 433, 458 (1976). Thus, it is at a criminal trial that the exclusionary rule's "remedial objectives are . . . most efficaciously served." Calandra, supra at 348. Exclusion of such evidence from a probation revocation hearing, however, would provide at most only marginal additional deterrence against police misconduct. See cases cited, supra. As one commentator has stated: "[I]t cannot realistically be supposed that a police officer, no matter how venal he [or she] may be, will refrain from obeying the law, thereby losing vital case-in-chief evidence, in the vain hope that in exchange he [or she] may obtain evidence which can only be used `should it subsequently appear that the victim of such conduct was a [probationer]'" (footnotes omitted). Cole, The Exclusionary Rule in Probation and Parole Revocation Proceedings: Some Observations on Deterrence and the "Imperative of Judicial Integrity," 52 Chi.-Kent L. Rev. 21, 36-37 (1975), quoted in Chase v. State, supra at 253. When the police officers involved in the illegal search and seizure neither know nor have reason to know of the search victim's status as probationer, the deterrent value of excluding the evidence from a probation revocation proceeding is absent. Winsett, supra at 54 n. 5. Payne v. Robinson, supra at 571. Cf. State v. Shirley, 117 Ariz. 105 (1977) (exclusionary rule applies when officers conducting illegal search and seizure knew of probationer's status).

Olsen argues, however, that concern for judicial integrity precludes the use of illegally obtained evidence in any court proceeding whatsoever. See Elkins v. United States, 364 U.S. 206, 222-223 (1960). It does not appear that any of the cases in which illegally obtained evidence was held inadmissible to revoke probation explicitly relied on a concern for judicial integrity. See United States v. Rea, 678 F.2d 382 (2d Cir. 1982); United States v. Workman, 585 F.2d 1205 (4th Cir. 1978); State v. Shirley, supra; State v. Dodd, 396 So.2d 1205 (Fla. Dist. Ct. App. 1981), aff'd, 419 So.2d 333 (Fla. 1982); Ray v. State, 387 So.2d 995 (Fla. Dist. Ct. App. 1980); Adams v. State, 153 Ga. App. 41 (1980); Amiss v. State, 135 Ga. App. 784 (1975); State v. Burkholder, 12 Ohio St.3d 205, cert. denied, 469 U.S. 1062 (1984); Michaud v. State, 505 P.2d 1399 (Okla. Crim. App. 1973); Rushing v. State, 500 S.W.2d 667 (Tex.Crim. App. 1973). A few dissenting opinions decry the use of illegally obtained evidence in any proceeding as a matter of judicial integrity. See, e.g., Bazzano, supra at 846 (Gibbons, J., dissenting); United States v. Hill, 447 F.2d 817, 819 (7th Cir. 1971) (Fairchild, J., dissenting); Dowery, supra at 208-210 (Goldenhersh, J., dissenting); Caron, supra at 505-506 (Dufresne, C.J., dissenting). We believe, in the circumstances of this case, the imperative of judicial integrity is adequately served by the exclusion of illegally obtained evidence at trial.

Our decision in Commonwealth v. Fini, supra, is not to the contrary. In Fini, we concluded that evidence obtained through illegal electronic eavesdropping in a private home is inadmissible, under art. 14 of the Declaration of Rights, to impeach a defendant's testimony at trial. See Commonwealth v. Blood, 400 Mass. 61, 68-71 (1987) (evidence derived from illegal electronic surveillance inadmissible in Commonwealth's case-in-chief). We stated in Fini, supra at 573, that "half measures of deterrence are not enough," and that "the exclusion of such [illegally obtained] evidence for all purposes will act as a still further deterrent." Despite our broad language, it is clear that we were referring to "all purposes" at trial. In the next sentence, we stated: "Such a rule would tend to discourage the gathering of such evidence based on the hope that it will reach the jury in one way if not in another." Id. All that was before us in Fini was the use of electronic eavesdropping evidence at trial; we did not decide any other issue.

We note that this case does not involve egregious police conduct, Thompson v. United States, 444 A.2d 972 (D.C. 1982), or conduct that "shock[s] the conscience." In re Martinez, 1 Cal.3d 641, 649-652 (1970). Our decision should not be taken as an invitation to harassment. People v. Watson, 69 Ill. App.3d 487 (1979). Dulin v. State, 169 Ind. App. 211 (1976). We expressly leave open the question whether the police officer's knowledge of the probationer's status would compel a different result. See Payne v. Robinson, 207 Conn. 565, 573 (1988); and compare State v. Caron, 334 A.2d 495, 502 (Me. 1975) (Dufresne, C.J., dissenting).

Our decision protects the availability of probation for offenders. If we were to exclude that evidence from probation revocation hearings, there might be a disinclination to order probation in the first place. See People v. Dowery, 20 Ill. App.3d 738, aff'd, 62 Ill.2d 200 (1974); State v. Kuhn, 7 Wn. App. 190, aff'd, 81 Wn.2d 648 (1972). Our decision today also protects the public interest in having access to all reliable evidence relevant to the probationer's conduct and rehabilitation. Commonwealth v. Vincente, supra. Order revoking probation affirmed.