Appellant Dudley was found guilty by a jury of distribution of cocaine, possession with intent to distribute cocaine, and possession with intent to distribute marijuana. On appeal he challenges the refusal of the trial court to admit in evidence statements made by one of his codefendants, Antoinette Smith, at her aborted guilty plea proceeding and a similar statement Smith made to Dudley’s attorney. Both statements purported to exculpate Dudley of the drug sale and purchase for which he and Smith were charged (Smith with simple possession only). We find no error in the trial court’s exclusion of these statements, and affirm.
I. The facts
According to the government’s proof, on August 15,1998, two police officers concealed in an observation post saw Dudley’s code-fendants Smith and Freeman drive up in a car and stop near a group of people who were socializing and drinking. Smith got out of the car, approached a fence, and talked to *867Dudley. Dudley crossed the street, removed an object from the wheel well of a motorcycle trailer, returned to Smith at the fence, handed her the object, and received a different object from her. Smith returned to her car and drove off, but police stopped the car several blocks away. As they approached, they saw Smith throw what proved to be a bag of crack cocaine behind the seat, and saw Freeman attempt to conceal another bag of cocaine between the front seats. Freeman and Smith were arrested on drug charges, after which the officers returned to the group of socializers and arrested Dudley for selling drugs. They found 34 bags of crack and six bags of marijuana in the trailer wheel well.
II. Discussion
A. Prior cross-examined testimony.
Dudley’s first contention relates to statements made by Smith at a proceeding in which she intended to plead guilty to the lesser included charge of attempted possession of cocaine. In return for reduction of the charged offense, Smith was expected to give an “insulating statement” under oath in which she described the events of the purchase and named Dudley as the seller.1 The prosecutor asked Smith a few introductory questions and then whether, when she approached Dudley, she bought drugs from him. Smith answered “no” and explained that she sought out Dudley, whom she knew because their children played together, strictly to obtain change for a $10 bill at the request of a companion in her car. It was the companion, not Dudley, who purportedly gave her cocaine in return for her obtaining change. On hearing this testimony, the prosecutor told the court, “[Wje’re not prepared to accept this insulating statement,” and asked Smith no further questions. The court, recognizing that the plea had broken down, recessed the case to let Smith decide whether to plead guilty to the indictment. She later did so.
At Dudley’s trial, after it was confirmed that Smith was unavailable as a witness (she had failed to appear for her sentencing), Dudley’s counsel sought to introduce her statements at the aborted plea proceeding as prior cross-examined testimony. The trial judge ruled the statements inadmissible on that ground.
The proponent of the admissibility of prior testimony must demonstrate:
(1) that direct testimony from the declar-ant is unavailable; (2) that the declarant, when giving the prior testimony, was under oath in a legal proceeding; (3) that the issues in the two proceedings are substantially similar; and (4) that the party against whom the testimony is now offered had an opportunity to cross-examine the declarant at the earlier proceeding.
Bedney v. United States, 684 A.2d 759, 763 (D.C.1996). The first two requirements are not in issue here.
Equally important, however, is the requirement that the party against whom the testimony is now offered must have had in the prior proceeding an adequate opportunity to cross-examine the declarant. An adequate opportunity to cross-examine exists if the parties and the issues in both proceedings are substantially the same.
Epstein v. United States, 359 A.2d 274, 277 (D.C.1976). “Unless the issues were then [substantially] the same as they are when the former statement is offered, the cross-examination would not have been directed to the same material points of investigation, and therefore could not have been an adequate test for exposing inaccuracies and falsehoods.” Id. at 277-78 (quoting 5 Wigmore, Evidence § 1386, at 82 (3d ed.1940)) (emphasis deleted).
Smith’s testimony at the aborted plea proceeding did not meet this requirement. Her plea to the lesser charge depended on her giving an insulating statement satisfactory to the prosecutor. Dudley’s guilt or innocence was thus at issue only in a narrow sense: if Smith satisfied the prosecutor in linking Dudley to the sale (or at least in not *868exculpating him), her plea could proceed, otherwise it could not.2 The prosecutor’s questioning of Smith was therefore very limited.3 When Smith testified contrary to the prosecutor’s expectation, the plea ended and with it any issue — at that proceeding — of Dudley’s guilt. The prosecutor asked no further questions because she had no reason to; Dudley’s involvement in the sale had ceased to be a “material” issue in the proceeding. Wig-more, supra. Indeed, with the plea agreement having dissolved, it might well have been improper for the prosecutor to continue questioning Smith about Dudley’s complicity in the sale. See Alston v. United States, 383 A.2d 307, 312 n. 9 (D.C.1978) (at codefend-ant’s plea of guilty to indictment, prosecutor’s extensive questioning of him about defendant’s role in crime was “beyond the scope of proper guilty plea examination, apparently engaged in purely for discovery purposes, and should not have been condoned”).4
“In our cases in which the admission of prior recorded testimony has been allowed, the cross-examination has been generally broad and unrestricted.” Bedney, 684 A.2d at 765. The purpose of Smith’s plea proceeding made such cross examination pointless, if not improper; hence it did not occur.5 In short, the issues at this proceeding and at Dudley’s later trial were not substantially similar, id. at 763; Epstein, 359 A.2d at 277, and thus the exception for prior cross-examined testimony did not apply. See also Fed. R.Evid. 804(b)(1) (former testimony admissible if, inter alia, party against whom testimony is offered “had an opportunity and similar motive to develop the testimony by direct, cross, or redirect examination”) (emphasis added); cf. Hill v. United States, 664 A.2d 347, 351 n. 8 (D.C.1995) (before grand jury, government “may have had different motives in mind ... and not have been focused on the collateral issue of appellants’ standing to challenge the search”).
Our dissenting colleague is right, of course, that hearsay rules should be applied practically, not “mechanistically,” especially when constitutional rights are at stake. But we deal here with statements whose trustworthiness, hence admissibility, is grounded in the practical opportunity for prior cross-examination defined by the incentives which the party opposing admission had to challenge their reliability. Try as she may, our colleague cannot convert the questioning that took place into recognizable cross-examination. At almost exactly the place where true cross would have begun (using, to take but one example, prior inconsistent statements) the prosecutor ceased questioning and effectively ended the proceeding. She did so because the reason for the questioning — indeed, for the proceeding itself — had expired.
We thus do not decide the “abstract” question whether questioning designed to elicit an insulating statement ever may satisfy the hearsay exception in dispute, though the answer will likely be no in light of Alston’s admonition — not questioned by the dissent— against misuse of plea proceeding examination. We hold only that, consistent with the *869reason for Smith’s testimony, the prosecutor’s aborted questioning did not reflect the features of examination designed “to challenge whether the declarant was sincerely telling what [s]he believed to be the truth, whether [she] accurately perceived and remembered the matter [s]he related, and whether [her] intended meaning [was] adequately conveyed by the language [s]he employed.” Feaster v. United States, 631 A.2d 400, 406-07 (D.C.1993) (citations and internal quotation marks omitted). Dudley’s right to a fair trial did not require the jury to hear statements of such untested reliability.
B. Declarations against penal interest.
Dudley further argues that Smith’s statements at the plea proceeding and similar statements she made to Dudley’s attorney the same day amounted to declarations against her penal interest. This argument too is unavailing. “[A] statement tending to expose the declarant to criminal liability and offered as tending to exculpate the accused is admissible when the declarant is unavailable and corroborating circumstances clearly indicate the trustworthiness of the statement.” Laumer v. United States, 409 A.2d 190, 199 (D.C.1979) (en banc) (emphasis deleted). Smith’s exculpation of Dudley by itself, of course, was not against her penal interest, nor did it become so just by being conjoined with an admission of her own guilt. See Williamson v. United States, 512 U.S. 594, 599-600, 114 S.Ct. 2431, 129 L.Ed.2d 476 (1994). Although by refusing to give a satisfactory insulating statement Smith limited her options (she could now plead guilty only to possession, not attempted possession), we doubt seriously that this made her exculpatory statements sufficiently against her penal interest to meet the admissibility threshold. That question need not be answered, though, because Dudley failed to persuade the trial judge of the existence of “corroborating circumstances clearly indicat[ing] the trustworthiness of the statements].” Laumer, 409 A.2d at 199. We may reverse the latter determination only if clearly erroneous, id. at 203, and we find no such error here.
Affirmed.
. The government states in its brief that it routinely insists on obtaining such a statement as part of a plea agreement in cases involving multiple defendants. The purpose of the statement is to limit the pleading defendant’s ability later to change her testimony about the crime and exonerate codefendants.
. The prosecutor’s insistence on such a statement as a condition of the plea is not challenged. Cf Bordenkircher v. Hayes, 434 U.S. 357, 363, 98 S.Ct. 663, 54 L.Ed.2d 604 (1978).
. The questions the prosecutor asked Smith about buying drugs from Dudley were as follows:
Q: Now when you approached Mr. Dudley did you buy from him?
A: No ma'am.
Q: What did you do with respect to Mr. Dudley? ... [Smith tells the stoiy in narrative form]
Q: And is it your testimony today that you never received drugs from Mr. Dudley?
A: No I did not, ma'am.
Q: Your Honor, we're not prepared to accept this insulating statement.
. The trial court in the present case explained:
[W]e’re not talking about a circumstance where it would, I think, even be appropriate for the prosecutor to engage in a probing inquiry of the defendant regarding the defendant's statement.... I would believe that there would be a hue and cry from the defense bar if judges started to let the prosecutor under those circumstance^] then engage in a probing inquiry seeking to attack the credibility of the person when the person has indicated that they are not prepared to agree to the statement the Government asked them to agree to.
.We reject Dudley’s suggestion at oral argument that the prosecutor’s brief lead-in questioning of Smith in which Smith acknowledged that her child and Dudley's played together added significantly to the questioning about the drug transaction.