Hearsay declarations by a coconspirator made during the course and in furtherance of an alleged conspiracy may not be considered by a jury unless the prosecution has established a prima facie case of the alleged conspiracy without regard to the hearsay (People v Rastelli, 37 NY2d 240, 244 [1975], cert denied 423 US 995 [1975]). The majority concludes that the prosecution established a prima facie case of the alleged conspiracy independent of the testimony of George Castro, the alleged coconspirator, concerning declarations made by defendant. The majority further speculates that, rather than the conspiracy to commit murder charged in the indictment, Castro may have been an accomplice only in a separate conspiracy related to the earlier attempted murder of Ortiz. Neither contention is supported by the record.
The “independent” evidence of defendant’s participation in the murder conspiracy on which the majority relies consists of defendant’s “own admissions” and “strong circumstantial proof.” However, as defendant did not testify, nor did he confess to participating in any conspiracy, there were no “admissions” by defendant. The only evidence of the alleged conspiracy— including the circumstantial “proof” cited by the majority— came from Castro’s testimony as to the events allegedly leading up to the murder of Ortiz, events in which, according to Castro’s own testimony, he participated.
The majority speculates that, because the record is silent as to precisely when in March the attempted murder occurred, it might have taken place before the March 18 meeting at which the murder conspiracy was hatched, and, if so, that the attempted murder was part of a separate and distinct conspiracy. Under this scenario, Castro may have been an accomplice in the attempted murder conspiracy but not in the conspiracy to commit murder, and, therefore, defendant was not entitled to an accomplice-in-law instruction to the jury. Nothing in the record supports such a fanciful construct.
The undisputed evidence in this case—the testimony of George Castro, the single witness to the alleged conspiracy— *287establishes that Castro was present at the March 18 meeting where the conspiracy to kill Ortiz was first hatched; that Castro “acted as a lookout” in a foiled attempt by members of the conspiracy to murder Ortiz; and that, on June 1, the day the object of the conspiracy was consummated, he accompanied coconspirator Garcia as he proceeded to the park where Garcia shot and killed Ortiz. There is nothing in the evidence to suggest that there were two conspiracies, one related to the aborted murder attempt and the other concerning the successful murder. Rather, the evidence establishes that there was one conspiracy, the object of which was to kill Ortiz, and that Castro participated in the conspiracy. There is absolutely no evidence to support the majority’s double conspiracy theory.
A witness “may be an accomplice for corroboration purposes if he or she may reasonably be considered to have participated in an offense based upon some of the same facts or conduct which make up the offense on trial” (People v Berger, 52 NY2d 214, 219 [1981]; see also CPL 60.22 [2]). If the undisputed evidence establishes that a witness is an accomplice in the conspiracy charged, the witness is an accomplice as a matter of law (see People v Basch, 36 NY2d 154, 157 [1975]), and the jury must be instructed that it may not convict the defendant solely on the uncorroborated testimony of that witness. Since, in my view, the undisputed evidence establishes that there was one conspiracy and that Castro was a member of, and thus an accomplice in, that conspiracy, the jury should have been instructed that he was an accomplice as a matter of law and that they could not convict defendant solely on the basis of Castro’s uncorroborated testimony.
Although the error is not preserved, the failure of the court to give an accomplice-in-law instruction constitutes a fundamental error of law warranting interest-of-justice review. Such fundamental error, even if not of constitutional dimension, requires reversal of the judgment of conviction under the standards enunciated by the Court of Appeals in People v Crimmins (36 NY2d 230, 241 [1975]). Crimmins instructs with regard to nonconstitutional error that “every error of law (save, perhaps, one of sheerest technicality) is, ipso facto, deemed to be prejudicial and to require a reversal, unless that error can be found to have been rendered harmless by the weight and the nature of the other proof” (id.; see also People v Bailey, 58 NY2d 272, 278 [1983]; People v Vadell, 122 AD2d 710, 712 [1986]).
In this case, the only evidence of defendant’s guilt was the uncorroborated testimony of an accomplice to the alleged crime. As a matter of law, that testimony is insufficient to convict. *288Trial counsel’s failure to request an accomplice instruction or to move to dismiss for lack of corroboration did not render the error harmless; it simply compounded the error.
Because there was no independent evidence of defendant’s guilt, the judgment of conviction should be reversed and the indictment dismissed.