Rosellini, J.
The petitioner was charged as an accomplice in the unlawful delivery of a controlled substance. The trial court denied his motions to exclude statements made during the criminal transaction by the principal, who claimed his Fifth Amendment privilege and was therefore unavailable as a witness. The jury found the petitioner guilty and the Court of Appeals affirmed. State v. Parris, 30 Wn. App. 268, 633 P.2d 914 (1981).
The evidence shows that on May 14, 1979, one Milliron, an informant, contacted police officer Hurley and advised him that he had arranged a "buy" of heroin. Milliron telephoned William DeHart and was told that DeHart could obtain a half gram of heroin through his "source" and that they were to meet at the Taco Time in Olympia at 10 p.m. Hurley and Milliron drove together in a car to that address where DeHart joined them within a minute or two, arriving in his own vehicle. The Taco Time was closed or closing at that time. DeHart told Milliron and Hurley that his source would arrive in a few minutes and DeHart would arrange to go with him to get the drugs. He was given $100 in currency for this purpose. Very shortly a third car, a late model silver Oldsmobile station wagon, drove up and DeHart got into the front seat next to the driver. After a brief conversation DeHart got out of the car and advised Hurley and Milliron that "they" would return in about a half hour. He then got back in the car and it started to move away, but stopped after a few yards. The courtesy light came on, and [143]*143the inside of the vehicle was lighted up. Milliron was able to see and recognize the petitioner in the driver's seat. He saw DeHart take something from the pocket where he had put the money and hand it to the petitioner, but could not see the object itself. DeHart then got out of the car and the petitioner drove away. DeHart explained that the defendant did not want him in the car because his supplier would be made uneasy.
DeHart told Hurley and Milliron that the drugs were being gotten. Milliron testified that he asked DeHart: "Do you mean that John's going to get them?" Milliron could not recall how DeHart responded to that question. Milliron then asked: "Will it be more than a half hour?" and DeHart said that he did not think so. Milliron then asked: "Well, do you think he'll return with the drugs, or the money, and the quantity and quality would be accurate?" and DeHart replied: "Yes. I think so. There won't be any problem." When Milliron asked DeHart from whom the petitioner was going to get the drugs, DeHart said that he did not know.
They arranged to meet at the Taco Time a half hour later. DeHart drove off, but Hurley and Milliron remained at the scene. A half hour later DeHart returned, coming from behind the Taco Time. He parked his car, got out and brought the heroin to Hurley and Milliron on foot. At the same time, Hurley observed a silver Oldsmobile station wagon driving away from the other side of the Boulevard Tavern, located next door to the Taco Time.
A woman friend of the petitioner, with whom he was living at the time, testified that he had no automobile of his own and that she allowed him to use her silver Oldsmobile station wagon occasionally. She also testified that they frequented the Boulevard Tavern. She did not recall whether either had been at the tavern on the night of May 14, 1979. She said that Parris had no source of income known to her, other than money which she gave him.
The petitioner objected to the testimony of Milliron and Hurley describing their conversations with DeHart at the [144]*144scene of the crime. The objection was based on the theory that this testimony made DeHart a witness against the petitioner, one who could not be cross-examined because DeHart was claiming his Fifth Amendment privilege against self-incrimination; and thus the petitioner was deprived of his right to confront the witnesses against him.
The Superior Court found the testimony admissible, and this ruling was affirmed by the Court of Appeals, Division Two, which held that the trustworthiness of DeHart's statements was established in that they qualified as exceptions to the hearsay rule under ER 804(b)(3), as statements against his penal interests; that they bore other adequate "indicia of reliability," and accordingly satisfied Sixth Amendment requirements pursuant to the holding of Ohio v. Roberts, 448 U.S. 56, 65 L. Ed. 2d 597, 100 S. Ct. 2531 (1980). We granted a petition for review limited to this issue.
The sixth amendment to the United States Constitution guarantees the right of an accused in a criminal prosecution to confront witnesses against him. Davis v. Alaska, 415 U.S. 308, 315, 39 L. Ed. 2d 347, 94 S. Ct. 1105 (1974). The main and essential purpose of confrontation is to secure for the opponent the opportunity of cross examination. Davis, at 315, quoting from 5 J. Wigmore, Evidence § 1395, at 123 (3d ed. 1940). The purpose of such confrontation is to test the perception, memory and credibility of witnesses. Davis, at 316. Also, it serves the purpose of testing the witnesses' narrative powers. E. Cleary, McCormick on Evidence § 245 (2d ed. 1972). Where the witness is unavailable to testify, this right of confrontation may be violated if other witnesses testify to the substance of his statements. See generally Ohio v. Roberts, supra. On the other hand, the constitutional right to confrontation does not invariably exclude hearsay implicating the accused. Ohio v. Roberts, supra.
The Supreme Court of the United States has recently laid down the following criteria for constitutionally admissible hearsay statements:
[145]*145In sum, when a hearsay declarant is not present for .cross-examination at trial, the Confrontation Clause normally requires a showing that he is unavailable. Even then, his statement is admissible only if it bears adequate "indicia of reliability." Reliability can be inferred without more in a case where the evidence falls within a firmly rooted hearsay exception. In other cases, the evidence müst be excluded, at least absent a showing of particularized guarantees of trustworthiness.
(Footnote omitted.) Roberts, at 66.
The phrase "indicia of reliability" appears to have had its genesis in California v. Green, 399 U.S. 149, 26 L. Ed. 2d 489, 90 S. Ct. 1930 (1970). In Dutton v. Evans, 400 U.S. 74, 27 L. Ed. 2d 213, 91 S. Ct. 210 (1970), the Supreme Court delineated these indicia, after first observing that the confrontation clause does not prohibit a witness from testifying as to what he has heard as well as what he has seen. It is only when the out-of-court statement is offered for the truth of its content that confrontation problems arise. In Dutton, Evans had objected to testimony concerning a statement by an alleged accomplice, made to a fellow inmate after he was in custody, that had it not been for Evans "we wouldn't be in this now.'" Dutton, at 77.
The Court said:
The confrontation issue arises because the jury was being invited to infer that Williams had implicitly identified Evans as the perpetrator of the murder when he blamed Evans for his predicament. But we conclude that there was no denial of the right of confrontation as to this question of identity. First, the statement contained no express assertion about past fact, and consequently it carried on its face a warning to the jury against giving the statement undue weight. Second, Williams' personal knowledge of the identity and role of the other participants in the triple murder is abundantly established by Truett's testimony and by Williams' prior conviction. It is inconceivable that cross-examination could have shown that Williams was not in a position to know whether or not Evans was involved in the murder. Third, the possibility that Williams' statement was founded on faulty recollection is remote in the extreme. Fourth, the [146]*146circumstances under which Williams made the statement were such as to give reason to suppose that Williams did not misrepresent Evans' involvement in the crime. These circumstances go beyond a showing that Williams had no apparent reason to lie to Shaw. His statement was spontaneous, and it was against his penal interest to make it. These are indicia of reliability which have been widely viewed as determinative of whether a statement may be placed before the jury though there is no confrontation of the declarant.
Dutton, at 88-89. The Dutton Court said:
The decisions of this Court make it clear that the mission of the Confrontation Clause is to advance a practical concern for the accuracy of the truth-determining process in criminal trials by assuring that "the trier of fact [has] a satisfactory basis for evaluating the truth of the prior statement." California v. Green, 399 U. S., at 161.
Dutton, at 89. This court has recognized this fundamental principle. State v. Boast, 87 Wn.2d 447, 453, 553 P.2d 1322 (1976); State v. Kreck, 86 Wn.2d 112, 542 P.2d 782 (1975).
Five attendant circumstances were set forth in the case of United States v. Alvarez, 584 F.2d 694 (5th Cir. 1978) for use as guidelines in determining the trustworthiness of extra-judicial statements. These are: (1) whether there is an apparent motive to lie; (2) the general character of the declarant; (3) whether more than one person heard the statements; (4) whether the statements were made spontaneously; and (5) the timing of the declaration and the relationship between the declarant and the witness. These are not exclusive, of course, and should be considered in conjunction with the factors considered by the United States Supreme Court in Dutton v. Evans, supra.
The Court of Appeals in the present case as well as in the more recent case of State v. Valladares, 31 Wn. App. 63, 639 P.2d 813 (1982) concluded that because statements against penal interest have been included in Fed. R. Evid. 804(b)(3), which we have adopted verbatim, such statements form a "firmly rooted exception" to the hearsay rule. See Ohio v. Roberts, supra.
[147]*147ER 804(b)(3) provides:
(b) Hearsay Exceptions. The following are not excluded by the hearsay rule if the declarant is unavailable as a witness:
(3) Statement Against Interest. A statement which was at the time of its making so far contrary to the declarant's pecuniary or proprietary interest, or so far tended to subject him to civil or criminal liability, or to render invalid a claim by him against another, that a reasonable man in his position would not have made the statement unless he believed it to be true. A statement tending to expose the declarant to criminal liability and offered to exculpate the accused is not admissible unless corroborating circumstances clearly indicate the trustworthiness of the statement.
While finding that statements against penal interest qualify as firmly rooted exceptions to the hearsay rule, the Court of Appeals nevertheless found it prudent to read the rule as requiring corroboration, both where the statement is offered to inculpate and to exculpate the accused. This interpretation was necessary because, as we have seen, the United States Supreme Court has not found inculpatory statements of accomplices, standing alone, sufficiently reliable to warrant their admission. The Court of Appeals thought that the failure of Congress to make the corroboration requirement applicable to inculpatory statements stemmed "partly from a misreading of Supreme Court decisions regarding the confrontation clause and partly from legislative oversight." It cited Tague, Perils of the Rulemaking Process: The Development, Application, and Unconstitutionality of Rule 804(b) (3)'s Penal Interest Exception, 69 Geo. L.J. 851, 854 n.7 (1981); Comment, Federal Rules of Evidence 804(b)(3) and Inculpatory Statements Against Penal Interest, 66 Cal. L. Rev. 1189, 1190 n.7, 1216 n.156 (1978). See State v. Parris, 30 Wn. App. 268, 276 n.8, 633 P.2d 914 (1981).
The Fifth Circuit in United States v. Alvarez, supra, found the omission to be deliberate, rather than inadver[148]*148tent. That court said that the drafters of the federal rule left to the courts the task of delineating the requirements regarding admissibility of inculpatory statements, because of the constitutional question raised by the admission of such statements. This sensible explanation appears to us to be the more likely reason that the drafters made no attempt to define the circumstances under which inculpatory statements could be admitted.
It is not correct to say that inculpatory declarations are included within the "firmly rooted exceptions" to the hearsay rule. According to Ohio v. Roberts, supra at 66, if hearsay statements fall within a "firmly rooted exception" to the hearsay rule, they are admissible without "particularized guarantees of trustworthiness." Inculpatory statements must be accompanied by such guaranties in order to be admissible. Thus, we can only say that inculpatory statements are a "firmly rooted exception" if we add the proviso that they must be accompanied by corroborating circumstances clearly indicating their trustworthiness, or, in the words of the Supreme Court, "particularized guarantees of trustworthiness".1 This is a proviso required by substantive law, not one found expressed in the rule, and it places such statements in the second category of the Roberts test.
Whether this requirement is read into the rule, as was done in the Court of Appeals, or is simply recognized as a constitutional prerequisite to the admission of the evidence, the result is the same.
We turn then to the case before us. The petitioner does not question the fact that the statements were made. They were reported by two witnesses, both of whom were cross-examined with no apparent discrediting results. But it is argued that the statements made by DeHart did not amount to confessions of crime and were not made to per[149]*149sons whom he thought likely to use those statements against him; and for this reason they did not "so far [tend] to subject him to . . . criminal liability . . . that a reasonable man in his position would not have made the statement^] unless he believed [them] to be true." ER 804(b)(3).
In order to qualify as a statement against penal interest, a declaration need not have been a clear and unequivocal admission of criminal conduct.
In United States v. Barrett, 539 F.2d 244 (1st Cir. 1976), the defendant offered testimony by a witness, Melvin, which tended to exculpate him as a participant in the theft and sale of a stamp collection. The Court of Appeals for the First Circuit, holding that the remarks tended to subject Tilley to criminal liability to the extent " 'that a reasonable man in his position would not have made the statement unless he believed it to be true", said that although the remarks did not amount to a clear confession, they strongly implied the declarant's participation in the stamp crimes and hence would tend to subject him to criminal liability. "Though by no means conclusive, the statement would be important evidence against Tilley were he himself on trial for the stamp crimes". Barrett, at 251.
The court in Barrett also took account of the fact that the remarks were made in a conversation over cards, and that in such circumstances the speaker might not have readily perceived the disserving character of the remarks. Nevertheless, the court was unwilling to say that the circumstances "so far impugned the reliability presumed from the remarks' disserving character" as to take them outside the rule. Barrett, at 251. Upon remand the lower court was directed to examine the evidence, including other exculpatory evidence which the Court of Appeals ruled admissible, to determine whether there were circumstances "solidly indicating trustworthiness". Barrett, at 253.
The First Circuit's holding that the exception contained in rule 804(b)(3) is not confined to cases in which the declarant makes a "clear confession" does not stand alone. [150]*150In United States v. Alvarez, 584 F.2d 694 (5th Cir. 1978), the Court of Appeals held that statements made by a declarant (since deceased) talking on the telephone to a person identified by the declarant as the defendant, whom he had called for the purpose of setting up a drug transaction, were against his penal interest within the meaning of the rule. Citing United States v. Thomas, 571 F.2d 285 (5th Cir. 1978), the court said that the rule, by referring to statements that "tend to subject the declarant to criminal liability" (Thomas, at 288), encompasses disserving statements that would have probative value in a trial against the declarant. The court also cited Barrett, observing that, as in that case, the deceased's statements clearly indicated his participation, since they strengthened the impression that he had an insider's knowledge of the crimes. The Alvarez court, however, held that the trustworthiness of the testimony regarding those statements was not sufficiently established, there being among other considerations a "virtual dearth of [corroborating] circumstances". Alvarez, at 702.
Other cases holding that while a declarant's statements must, in a real and tangible way, subject him to criminal liability, the reach of rule 804(b)(3) is not limited to direct confessions of criminal responsibility include United States v. Bagley, 537 F.2d 162 (5th Cir. 1976) and United States v. Benveniste, 564 F.2d 335 (9th Cir. 1977).
While it is not the fact that the declaration is against interest but the declarant's awareness of the fact which gives the statement significance, courts have been willing to assume that a reasonable man would be aware of the dis-serving nature of his remarks even when they are made to a supposed friend. 4 J. Weinstein & M. Berger, Evidence ¶ 804(b)(3)[02], at 804-98 (1979). In United States v. Lang, 589 F.2d 92 (2d Cir. 1978), a statement made to an undercover agent indicating the witness' criminal conduct as a seller of counterfeit notes was held to be against his interest even though he was not aware that by making the statement he was subjecting himself to criminal liability. And in [151]*151United States v. Bagley, supra at page 165, it was held that a reasonable man would not falsely admit commission of a serious crime to his cellmate. The fact that the statement was made to a friend and cellmate has no relevance to the determination of whether the statement was against penal interest, the court said, but does bear on its trustworthiness.
On the other hand, the courts have been more suspicious of statements which, though they are against interest on their face, may actually have been made to gain an advantage, as when a person in custody makes a confession as part of a plea bargain. See United States v. Mackin, 561 F.2d 958 (D.C. Cir.), cert. denied sub nom. Gibson v. United States, 434 U.S. 959, 54 L. Ed. 2d 319, 98 S. Ct. 490 (1977); United States v. Gonzalez, 559 F.2d 1271 (5th Cir. 1977); United States v. Rogers, 549 F.2d 490 (8th Cir. 1976), cert. denied, 431 U.S. 918, 53 L. Ed. 2d 229, 97 S. Ct. 2182 (1977).
Judge Weinstein notes that rule 804(b)(3), in conjunction with rule 403 (ER 403), gives the court sufficient discretion to exclude statements if it finds that they are inherently unreliable because the particular declarant would not have had the requisite belief due to circumstances such as ignorance or currying favor. J. Weinstein & M. Berger, supra at 804-97.
Here the declarant, DeHart, undoubtedly knew that he was engaged in criminal conduct and that his statements would be against his interests were they to be repeated in court. His statements were all made in furtherance of the criminal act and were relevant in proving that a delivery had been made. He was evidently satisfied, however, that he was dealing with bona fide purchasers, rather than narcotics agents and presumably did not expect that his statements and acts would lead to his arrest. Nevertheless, there was no apparent motive for him to lie about the progress of the transaction, and the petitioner has suggested none. DeHart was not in custody, and had no reason to involve another in order to curry favor.
[152]*152We cannot perceive that a reasonable man in the same circumstances would have made these statements unless he believed them to be true. They were made spontaneously as natural steps in the progress of the transaction into which he had voluntarily entered and in which he could expect retaliation if his predictions did not materialize.
The statements would have probative value in a prosecution of DeHart (United States v. Alvarez, supra; United States v. Thomas, supra) and the circumstances did not "so far [impugn] the reliability presumed from the remarks' disserving character" as to take them outside the rule. United States v. Barrett, supra at 251. The surrounding circumstances point to the trustworthiness of the statements.
As the Court of Appeals in State v. Valladares, 31 Wn. App. 63, 71, 639 P.2d 813 (1982) correctly held, corroboration can be found in other evidence of guilt. There were, in addition, as the Court of Appeals found, sufficient corroborating circumstances to establish the trustworthiness of the assurances given by DeHart.
The petitioner was charged as an accomplice in the delivery of the heroin, and the jury was instructed that, in order to convict him, it must find that DeHart delivered a controlled substance. It was instructed that the petitioner was an accomplice if, with knowledge that it would promote or facilitate the commission of the crime, he aided or agreed to aid another person in planning or committing the crime, and that the word "aid" means all assistance whether given by words, acts, encouragement, support or presence. The correctness of that instruction has not been questioned.
The strongest corroborating circumstances here, of course, were that the petitioner appeared at the Taco Time at precisely the time when DeHart had told Milliron and Hurley that he would be meeting his "source", giving rise to the all but inescapable inference that he was there by appointment; that he received some object from DeHart, which was taken from the pocket in which DeHart had placed the money given him for the drug purchase; and [153]*153that his vehicle again was seen being driven away from the scene at the announced time for the delivery, that being the time when the delivery was made. Had DeHart made no statement expressly or impliedly implicating him in the delivery, these circumstances would have been sufficient to support a guilty verdict.
The statements attributed to DeHart amounted to no more than assurances that the situation was what it appeared to be—that the petitioner was his "source" who would procure the drug. As in Dutton v. Evans, 400 U.S. 74, 27 L. Ed. 2d 213, 91 S. Ct. 210 (1970), they contained no express assertion about a past fact and purported to be no more than a statement of expectations. In the absence of any other explanation—and the petitioner has offered none—his presence at the scene at the two significant times for the apparent purpose of keeping an appointment with DeHart was ample corroborating evidence to establish his complicity.
The petitioner has offered the court no suggestion of any responses discrediting DeHart or exculpating the petitioner which he could reasonably have hoped to elicit from DeHart, had an opportunity for cross examination been afforded him. Cross examination could hardly be expected to reveal that DeHart did not know what the petitioner's avowed intentions were; and the petitioner offers no motive which DeHart might have had for lying about those intentions. Under the circumstances of this case, the lack of an opportunity to cross-examine DeHart detracted little, if anything, from the accuracy of the truthfinding process.
In Dutton v. Evans, supra, the Court in determining that the hearsay evidence offered there was admissible, observed that the case did not involve the use, or misuse, of a confession made in the coercive atmosphere of official interrogation; that it did not involve any suggestion of prosecutorial misconduct or even negligence; that it did not involve use by the prosecution of a paper transcript; that it did not involve a joint trial; and that it did not involve the wholesale denial of all cross examination, these being sig[154]*154nificant features of cases in which the court had held hearsay evidence inadmissible.
All of these statements are true with regard to the case before us.
As modified herein, the decision of the Court of Appeals, Division TwOj is affirmed.
Brachtenbach, C.J., Stafford, Dolliver, and Dimmick, JJ., and Cochran, J. Pro Tern., concur.