(concurring). I agree with the majority that the testimony in issue in this case is hearsay, but that it is admissible because it *657is excluded from the hearsay rule as an adoptive admission. I disagree with the majority’s conclusion that admission of the testimony did not violate the defendant’s constitutional right to confront and cross-examine the witnesses against him. I would remand the case to the court of appeals to determine whether this violation of the defendant’s constitutional right was harmless beyond a reasonable doubt and to consider, if necessary, the other issues not yet decided.
The majority correctly points out that there is a two-part test for determining whether the confrontation clause has been satisfied: first, the declarant must be shown to be unavailable as a witness; second, the testimony admitted must be shown to have sufficient indicia of reliability. Pages 652, 653. The majority acknowledges that the first prong of the test has not been satisfied in this case, because there was no showing that the declarant was unavailable. The majority does not consider the question of unavailability, however, because the defendant “waived this question on appeal” since he did not raise the confrontation argument at the trial. Page 654.
I do not think this court should review, as a matter of discretion, only part of the constitutional issue in this case.1 The requirement that the state show that the *658hearsay declarant is “unavailable” is in most cases an indispensable part of the confrontation rule. Ohio v. Roberts, 448 U.S. 56, 74-75 (1980) ; State v. Bauer, 109 Wis. 2d 204, 210-211, 325 N.W.2d 857 (1982). The limited circumstances in which the court may dispense with the requirement of showing that the witness is unavailable are not present here. Hagenkord v. State, 100 Wis. 2d 452, 474-75, 302 N.W.2d 421 (1981) ; State v. Olson, 75 Wis. 2d 575, 591-93, 250 N.W.2d 12 (1977).
I disagree with the majority’s conclusion on the second part of the confrontation test for two reasons. Neither adoptive admissions in general nor the testimony in this case meets the standards of truthworthiness and reliability set forth in Ohio v. Roberts.
This hearsay exception is not “firmly rooted” merely because it is “long established in Wisconsin.” To determine whether an exception is “firmly rooted,” the court should determine whether the hearsay exception guarantees that the evidence admitted is trustworthy and reliable to the degree necessary to satisfy the requirements of the confrontation clause. State v. Bauer, 109 Wis. 2d 204, 213, 325 N.W.2d 857 (1982) ; State v. Dorcey, 103 Wis. 2d 152, 170, 307 N.W.2d 612 (1981) (Abrahamson, J., dissenting).
*659The adoptive admission hearsay exclusion does not withstand rigorous constitutional analysis. Allowing admissions by silence appears to be based on the idea that he who is silent appears to consent (“qui tacet consentiré videtur”). Courts and commentators uniformly stress that the legal maxim does not guarantee the reliability of an adoptive admission consisting of silence. Gullickson v. State, 256 Wis. 407, 411, 41 N.W.2d 291 (1950). As Judge Weinstein notes, the theory underlying the admission — “the normal human reaction would be to deny such a statement if untrue” — is a generalization, the truth of which must be tested in each case. The reliability of an admission by silence “turns on a number of factors including the circumstances in which the accusation is made, by whom it is made, and the physical and psychological state of the particular person involved.” 4 Weinstein’s Evidence par. 801(d)(2)(B) [01], p. 801-145 (1981). Testimony as to defendant’s silence “should be received and applied with caution— especially where the statements have been made, not by a party to the controversy, but by a stranger thereto.” Jones, The Law of Evidence, sec. 13:49, p. 526 (1982), note omitted.
Even if the adoptive admission hearsay exclusion itself does not guarantee that the evidence is truthworthy and reliable, the evidence may satisfy the confrontation clause because the evidence may be admitted upon a showing of “particularized guarantees of trustworthiness.” State v. Bauer, swpra, 109 Wis. 2d at 214; Hagenkord v. State, supra, 100 Wis. 2d at 476; State v. Olson, supra, 75 Wis. 2d 589-91. Such a particularized showing was not made in this case. The admission in this case was the defendant’s non-response to a statement implying that the defendant was part of a contract to kill. The majority rests primarily on the nature of the statement. The majority reasons that anyone who is innocent *660of being part of a contract to kill would certainly not be silent. That reasoning is troublesome in this case because, as the court of appeals pointed out, the testimony about the defendant’s conversation with the absent declarant is unclear and confusing.
The majority also states that the statement was corroborated because other witnesses testified that the defendant was involved in the shootings. That may be true, but the other testimony does not corroborate the specific inference of the statement that the defendant was part of a contract murder which may have supplied the requisite intent for first-degree murder.
The majority further reasons that the defendant already had an opportunity to confront the absent declar-ant. I fail to see how the defendant’s being in the presence of the person who made the statements which the defendant purportedly adopted amounts to the defendant’s opportunity, provided for in the federal and state constitutions as part of the accused’s right to a fair trial, to confront the witnesses. If the defendant’s opportunity to confront the nontestifying witness at some point prior to trial satisfies the confrontation clause, then the constitutional right will be meaningless in any case where the defendant “adopts” by silence a statement of the declarant while in the declarant’s presence. This court and the United States Supreme Court have consistently used the term “confront” to mean confront the witness in a setting in which the witness is subject to adversarial cross-examination. This court has also stated that “[tjhere is some question as to whether the mere opportunity to cross-examine satisfies the confrontation clause.” State v. Bauer, supra, 109 Wis. 2d at 220, n. 11.
It is also important to remember that in this case the circuit court did not admit the disputed testimony as hearsay, a hearsay exception, or hearsay satisfied. State v. Alles. 106 Wis. 2d 368. 379. n. 3. 316 N.W.2d *661378 (1982). It admitted the entire testimony of the witness to provide a contextual background for the defendant’s statements. Consequently the circuit court never determined, as a preliminary matter, whether sufficient foundational facts had been introduced to allow the jury reasonably to infer that the “accusatory” statement was made in the defendant’s presence, that the defendant understood the statement and had an opportunity to deny it, and that the circumstances were such that an innocent defendant would normally be induced to respond. 4 Wigmore, Evidence sec. 1071 (Chad-bourn rev. 1972).
Moreover, the circuit court did not instruct the jury how it should consider the adoptive admission evidence. I believe that ordinarily in cases where there is evidence admitted as an adoptive admission the jury should be instructed that the adoptive admission must be based on a proper foundation of facts (described above), that the accusatory statements are not received for the purpose of proving their truth, and that unless the jury finds that the defendant’s conduct indicated an admission that the accusatory statement was true the jury should disregard the statement.2 People v. Vindiola, 158 Cal. Rptr. 6, 12, 13, 96 Cal. App 3d 384 (1979). See also 4 Wig-more, Evidence sec. 1071 (Chadbourn rev. 1972).
Because the admission of this evidence violated the defendant’s rights for the reasons stated, I would remand to the court of appeals to allow the parties to brief *662the question of whether the error was harmless, for a decision on that issue, and if necessary for decision on the other issues raised on appeal.
Even though the defendant did not raise the confrontation argument at trial and waived the right to assert on appeal that the state had not met the first prong of the confrontation clause test, the majority considers the second prong stating only that the defendant “has not waived his entire confrontation argument." Page 654. The majority cites no authority for this “partial waiver” doctrine. It appears that the majority relies on the rule of appellate practice that the defendant by failing to preserve the issue at the trial waived appellate review as a matter of right, but that this court may nevertheless review his arguments as a matter of discretion, Manson v. State, 101 Wis. 2d 413, 417, n. 2, 304 N.W.2d 729 (1981). The majority apparently chooses not to *658exercise its discretion to review the unavailability half of the issue because its resolution would depend on the development of a factual record which was not made. The state was not notified at trial that it should prove unavailability. The majority apparently concludes that it would be unfair under the circumstances to hold against the state on appeal. The majority seems to exercise its discretion to review the second part of the confrontation issue because that half presents only a question of law. I think that the same problem that prevents the majority’s consideration of the first half of the issue should also prevent its consideration of the second. As I shall explain later, the necessary record was also not made on the second part of the issue.
“Despite the offhand appeal of this kind of evidence, the courts have often suggested that it be received with caution and have surrounded it with various restrictions and safeguards. . . . [W]hile in theory the statement is not offered as proof of its contents but rather to show what the party acquiesced in, the distinction is indeed a subtle one; the statement is ordinarily very damaging, and substantial assurances are required that acquiescence did in fact occur.” McCormick, Law of Evidence sec. 270, p.652 (2d ed. 1971) (notes omitted).