dissenting:
I respectfully dissent from Part II of the court’s opinion. I would reverse appel*223lant’s conviction for distribution of dilaudid and remand for a new trial.
I.
The principal issue is whether the government properly could have elicited “other crimes” evidence against appellant, softened by the protections the trial court’s ruling would have afforded. Defense counsel proffered that appellant’s alibi witness, his girlfriend Linda Koonce, would testify that appellant was wearing different clothing on the night of the crime from the clothing described by Officer Moroney. Counsel reasonably anticipated that the prosecutor would ask Koonce, on cross-examination, how she remembered what appellant was wearing. Counsel further anticipated that Koonce would reply she remembered because appellant had been released from jail the day before and had not changed his clothes overnight. Counsel accordingly sought a trial court ruling in limine to prohibit the prosecutor from asking Koonce how she remembered the clothing. Counsel reasoned that this question lacked probative value for the government but, by eliciting other crimes evidence, would be highly prejudicial to the defense. Drew v. United States, 118 U.S.App.D.C. 11, 15-16, 331 F.2d 85, 89-90 (1964). Although neither the trial court nor the prosecutor doubted Koonce’s proffered response, the court denied counsel’s request. As a consequence, counsel made a tactical judgment not to have Koonce testify, reasoning on the basis of counsel’s experience that other crimes evidence is devastating even if explicably innocuous, as in this case, by reference to dismissal of the charges for which appellant had been jailed.1
II.
Before addressing the merits, we are obliged to resolve whether, by failing to call Koonce to testify for the defense, appellant waived the right to challenge the trial court’s ruling. See Luce v. United States, 469 U.S. 38, 105 S.Ct. 460, 463-64, 83 L.Ed.2d 443 (1984) (by not testifying at trial, defendant did not “preserve for review the claim of improper impeachment with a prior conviction,” since on basis of trial court’s in limine ruling it was conjectural whether court would have allowed the impeachment); United States v. DiMatteo, 759 F.2d 831, 832-33 (11th Cir.) (per curiam), cert. denied, — U.S. —, 106 S.Ct. 172, 88 L.Ed.2d 143 (1985) (applies Luce’s rationale to foreclose review of in limine ruling allowing extrinsic evidence to impeach defense witness who did not testify).
Whatever our answer to that question would be if the trial took place today, I am satisfied that appellant has not waived his right to challenge the ruling in this case. Without doubt, the trial court’s ruling caused defense counsel to withhold the witness. It was clear, moreover, how the trial court would have ruled if counsel had called Koonce as a witness and the prosecutor had begun to cross-examine; appellant’s stay at the D.C. Jail would have come out, albeit with some restrictions. Thus, appellant’s concerns were not conjectural. Compare Luce, 105 S.Ct. at 463.2 *224Moreover, precedent in this jurisdiction at the time of appellant’s trial permitted a nontestifying defendant to challenge on appeal a trial court ruling that allegedly caused the defendant not to testify. Johns v. United States, 434 A.2d 463, 467-68 (D.C.1981); United States v. Lipscomb, 226 U.S.App.D.C. 312, 332-33, 702 F.2d 1049, 1069-70 (1983). By analogy, these cases also would permit the appeal of a ruling that demonstrably caused a defendant not to call a key witness. Thus, Luce —even if applicable 3 — represents a “ ‘clear break with the past,’ ” Brodis v. United States, 468 A.2d 1335, 1336, 1337 (D.C.1983) (citing United States v. Johnson, 457 U.S. 537, 549 (1982) (quoting Desist v. United States, 394 U.S. 244, 248, 89 S.Ct. 1030, 1033, 22 L.Ed.2d 248 (1969)). Accordingly, I would hold that Luce applies prospectively, if at all, and thus does not bar this appeal of the in limine ruling on the other crimes issue. Compare United States v. Givens, 767 F.2d 574, 577-79 (9th Cir.), cert. denied, — U.S. —, 106 S.Ct. 321, 88 L.Ed.2d 304 (1985) with United States v. Dunbar, 767 F.2d 72, 74-75 (3d Cir.1985) and DiMatteo, 759 F.2d at 832-33.4
III.
I turn to the merits. The witness’ expected answer would not have helped the government discredit appellant’s alibi; indeed, it would have added to Koonce’s credibility by demonstrating a concrete basis for her recall. But the answer also would have severely prejudiced appellant by implying he had a criminal propensity. The obvious net result would have been to damage appellant with other crimes evidence which the government had no right to introduce. The only fair ruling, therefore, would have been to disallow the prosecutor’s question on cross-examination, since it would have had no legitimate probative value for the government, only illegitimate value by prejudicing the defense. See United States v. Bussey, 139 U.S.App.D.C. 268, 272, 432 F.2d 1330, 1334 (1970) (reversible error for court to permit government’s rebuttal witnesses not only to undermine alibi by placing appellant elsewhere but also to testify appellant was committing crime there); cf. Brown v. United States, 387 A.2d 728, 730-31 (D.C.1978) (error but not plain error when detective’s references to “photographs” and “custody” “convey[ed] to the jury the impression” that appellant “had a criminal record”).
The cases cited by the majority underscore the importance of a sound trial court ruling premised on the rule that other crimes evidence is presumed prejudicial and thus inadmissible unless it serves a “substantial, legitimate purpose.” Drew, 118 U.S.App.D.C. at 15-16, 331 F.2d at 89-90. For the government to establish such a *225purpose, usually one of the time-honored exceptions (irrelevant here) must apply, such as evidence of motive, identity, or common scheme. Drew, 118 U.S.App.D.C. at 16, 331 F.2d at 90; Bracey v. United States, 79 U.S.App.D.C. 23, 26, 142 F.2d 85, 88, cert. denied, 322 U.S. 762, 64 S.Ct. 1274, 88 L.Ed. 1589 (1944). Otherwise, there must be a clear showing that the probative value to the government outweighs the prejudicial impact on the defense. Brown, 387 A.2d at 730; Bussey, 139 U.S.App.D.C. at 272, 432 F.2d at 1334; see United States v. Williamson, 482 F.2d 508, 514 (5th Cir.1973).
Accordingly, unless the government can show a legitimate connection between the two crimes, the prosecutor must present the case-in-chief “ ‘with scrupulous care to avoid any intimation to the jury’ ” that a defendant had engaged in another crime “immediately before the one at issue.” Bussey, 139 U.S.App.D.C. at 272, 432 F.2d at 1334; Hood v. United States, 125 U.S. App.D.C. 16, 18, 365 F.2d 949, 951 (1966).5
Once a defendant has presented his or her defense, however, the government may perceive a need to elicit testimony on cross-examination or in rebuttal that is likely to inject evidence of the defendant’s other crimes. In fairness to the government, such testimony occasionally may be permitted to avoid a defense advantage, but only if the trial court soundly rules, after a proffer, that “the other crimes evidence [is] ‘necessary’ and therefore admissible despite its inflammatory content.” Bussey, 139 U.S.App.D.C. at 273, 432 F.2d at 1335. Thus, cross-examination or rebuttal “evidence which incidentally reveals the commission of a crime other than the one named in the indictment may ... be received if it tends to defeat the defensive theory or rebut an issue raised by the defense.” Bracey, 79 U.S.App.D.C. at 28, 142 F.2d at 90 (footnote omitted).
For example, in Hood, 125 U.S.App.D.C. at 18, 365 F.2d at 951, the prosecutor properly elicited on cross-examination of an alibi witness that appellant had robbed that witness in the same neighborhood, several minutes before the crime at issue. The government is “free to develop any facts ... which tend[ ] to make [the testimony] unavailable as an alibi.” Id. In contrast, in Bussey, 139 U.S.App.D.C. at 270, 272-73, 432 F.2d at 1332, 1334-35, the trial court abused its discretion by permitting the government to elicit testimony from rebuttal witnesses (who refuted an alibi supplied by appellant’s girlfriend) that appellant not only was elsewhere shortly before the time of the charged offense but also was committing a crime there. The court noted that the reference to the earlier alleged crime was unnecessary to rebut the alibi. 139 U.S.App.D.C. at 272, 432 F.2d at 1334. The court added, however, that the situation might have been different if the government had properly limited the testimony on direct, then defense counsel, on cross-examination, had “cast doubt on the rebuttal witnesses’ recollection,” and then the government, on redirect, had asked the witnesses for particulars demonstrating why “they definitely remembered” where appellant was. 139 U.S.App.D.C. at 273, 432 F.2d at 1335.
In the present case, the alibi witness’ anticipated reference, on cross-examination, to appellant’s previous day in jail — a wholly collateral matter — in no way would have “tend[ed] to defeat the defensive theory or rebut an issue raised by the defense.” Bracey, 79 U.S.App.D.C. at 28, 142 F.2d at 90 (footnote omitted). Appellant’s previous day in jail was altogether irrelevant to his misidentification defense, except to help establish, not impeach, his witness’ credibili*226ty. Compare Hood, 125 U.S.App.D.C. at 18, 365 F.2d at 951. In short, the prosecutor’s anticipated question would not even have been probative, let alone “necessary,” for the government, and thus should have been barred in limine, given the “inflammatory content” of the witness’ proffered answer. Bussey, 139 U.S.App.D.C. at 273, 432 F.2d at 1335.6
Accordingly, I conclude — based exclusively on the cases cited by the majority— that the trial court erred in denying appellant’s motion to exclude the prosecutor’s anticipated question. Because the error caused appellant to withhold a key witness, it was of a magnitude requiring reversal — a clear abuse of discretion. Johnson v. United States, 398 A.2d 354, 363, 364 (D.C.1979).
. In United States v. Bussey, 139 U.S.App.D.C. 268, 273, 432 F.2d 1330, 1335 (1970), the court recognized the considerable unfairness of admitting evidence of a defendant’s "alleged crime which had not been reduced to a final judgment.”
. Luce v. United States, 469 U.S. 38, 105 S.Ct. 460, 462, 83 L.Ed.2d 443 (1984), pertained to a conjectural trial court ruling, for it was unclear whether the defendant would have testified, id., or how the defendant would have testified, id., or, as a consequence, how the trial court would have exercised its discretion to admit or exclude prior convictions under Fed.R.Evid. 609(a). In the present case, however, but for the trial court’s ruling, there is no doubt that appellant’s alibi witness would have testified, and, given that ruling, there is little if any doubt that the other crimes evidence would have come out on cross-examination. Furthermore, Luce dealt with admissibility of a prior conviction that unquestionably would have had legitimate impeachment value, whereas in this case the other crimes evidence would have been illegitimately prejudicial. Thus, appellant had a much stronger reason for questioning the trial court’s ruling than Luce did.
. But see supra note 2.
. United States v. Givens, 767 F.2d 574, 577-79 (9th Cir.), cert, denied, — U.S. —, 106 S.Ct. 321, 88 L.Ed.2d 304 (1985), held that Luce should not apply retroactively where the defendant reasonably relied on Ninth Circuit precedent permitting appeal of an in limine ruling that prior convictions were admissible under Fed.R.Evid. 609. The record showed that the defendant would have testified but for the adverse ruling. It also contained the defendant’s proffered testimony, which was sufficient to show the basis for the trial court's ruling.
In contrast, United States v. Dunbar, 767 F.2d 72, 74-75 (3d Cir.1985), applied Luce retroactively because the defendant could not reasonably rely on a weak Third Circuit precedent, in a footnote, suggesting unconditional review of in limine rulings on admissibility of prior convictions. But see id., 767 F.2d at 76-78 (Adams, J., dissenting). Furthermore, the defendant in Dunbar was not certain to testify but for the trial court's adverse ruling; counsel merely said she was "considering" whether to call him as a witness. Id., 767 F.2d at 75.
Finally, United States v. DiMatteo, 759 F.2d 831, 832-33 (11th Cir.) (per curiam), cert. denied, — U.S. —, 106 S.Ct. 172, 88 L.Ed.2d 304 (1985), merely applied Luce retroactively without analysis. An earlier opinion in the same case, however, made clear that there was no precedent in the Eleventh Circuit on which the defendant could have relied to appeal an adverse ruling in limine when he declined to call the witness whose impeachment with extrinsic evidence that ruling would have allowed. United States v. DiMatteo, 716 F.2d 1361, 1365 (11th Cir.1983).
. This general proposition has a major exception that is irrelevant here: two criminal charges may be properly joined at trial when they are easily triable as separate offenses, even though evidence of one has no bearing on the other. E.g., Cox v. United States, 498 A.2d 231, 235 (D.C.1985). (Such a joinder is also permissible, of course, when the evidence of each crime would be admissible in a separate trial of the other, applying Drew criteria. Cox, 498 A.2d at 235.)
. If, as the trial progressed, the government could have clearly demonstrated a need to elicit the anticipated answer to discredit Koonce, then the prosecutor could have asked the court for permission to pin down why Koonce "definitely remembered” what appellant was wearing. Bussey, 139 U.S.App.D.C. at 273, 432 F.2d at 1335. But, on this record, the government has not shown why the question was "necessary.” Id.