After a joint jury trial with Russell H. Sykes and other defendants, Herbert Gibson was convicted of conspiracy to distribute cocaine, distribution of cocaine, and possession with intent to distribute marijuana, in viola*594tion of D.C.Code § 33-541(a)(l) (1993); Sykes was convicted of conspiracy to distribute cocaine.1 Gibson and Sykes contend on appeal: (1) that the trial court improperly refused to permit adequate voir dire questioning into the relationships between prospective jurors and law enforcement personnel; (2) that the trial court erred in limiting the scope of a Jencks2 inquiry and in failing to compel the production of all relevant Jencks material to trial counsel; and (3) that the evidence was insufficient to support their conspiracy convictions. Gibson also maintains that the marriage of his trial counsel to a police officer — which was not disclosed to Gibson until after the trial was underway and only after Gibson had observed his trial counsel’s husband fraternizing with other police officer witnesses in the ease — presented a conflict of interest which abridged his Sixth Amendment right to effective assistance of counsel. We find persuasive the voir dire argument made by appellants. Accordingly, we reverse their convictions and remand their cases for new trials.3 In view of our disposition, it is not necessary for us to reach the remaining issue raised on appeal.

I.

During the voir dire phase of jury selection, the government’s attorney introduced to the panel of prospective jurors eight witnesses the government intended to call to testify in its case-in-chief. Seven of the eight witnesses were police officers and one was a civilian. Thereafter, thirteen prospective jurors stated that they or a close relative had been directly involved in law enforcement.4 The trial court asked the prospective jurors with connections to law enforcement whether any member would be inclined to give either greater or lesser weight to the testimony of a police officer merely because the person testifying was a police officer; no one responded affirmatively. When counsel for codefendant Harris requested the trial court to ask follow-up questions to those prospective jurors and to grant permission for him to inquire further about a prospective juror’s daughter, who was employed as a metropolitan police officer, the court denied the requests. In denying the requests, the trial court noted the negative response by the panel to the court’s follow-up question. The dialogue between the trial court and defense counsel, who was interrupted by the trial court as he attempted to explain his point, was as follows:

MR. MCMILLEN: My point is, Your Honor—

*595THE COURT: I know what your point is. It doesn’t impress me.

* * * * * *

THE COURT: You have your thoughts on the record. I want to seat the jury now.

MR. MCMILLEN: Very well, your honor.

THE COURT: This isn’t Maryland.

II.

Gibson contends that the trial court erred in not permitting any follow-up questioning of the thirteen prospective jurors who stated that either they or a close relative had been directly involved in law enforcement. The government contends that this court must apply the “plain error” standard since no objection was made at trial. While counsel for neither Gibson nor Sykes objected to the adequacy of voir dire at trial, and plain error is ordinarily applied in such circumstances, Harris v. United States, 602 A.2d 154, 159 (1992) (en banc); see also Watts v. United States, 362 A.2d 706, 709 (D.C. 1976) (en banc) (to justify reversal under this standard, “the error[s] complained of must be so clearly prejudicial to substantial rights as to jeopardize the very fairness and integrity of the trial”), we reject the plain error standard in the present case.

This court has held that an objection is preserved when made by a codefendant. (Kirk) Williams v. United States, 382 A.2d 1, 7 n. 12 (D.C. 1978) (if a codefendant has raised an objection, the purposes of the plain error rule — presentation of the issues by the prosecution and review by the trial court— may be satisfied and the defendant’s failure to object overlooked); Perkins v. United States, 446 A.2d 19, 25 n. 4 (D.C. 1982) (same).5 Moreover, when “counsel has attempted to proffer a particular type of evidence [or objection] and the trial court has made its unwillingness to entertain a proffer absolutely clear, [co-] counsel should not be expected to risk contempt by pressing further to make an offer of proof [or to preserve that objection].” See McBride v. United States, 441 A.2d 644, 657 (D.C. 1982). Since the trial court record reveals clearly that appellants’ codefendant, Harris, made the objection, thereby preserving that objection for appellate court review, we measure this case against the “harmless error standard” as set forth in Chapman v. California, 386 U.S. 18, 24, 87 S.Ct. 824, 828, 17 L.Ed.2d 705 (1967). Williams, supra, 382 A.2d at 7 n. 12. Applying this standard, we hold that the error complained of did contribute to the verdict obtained. Chapman, supra, 386 U.S. at 24, 87 S.Ct. at 828.

III.

We recognize that the trial court has broad discretion inf conducting voir dire examination. Jenkins v. United States, 541 A.2d 1269, 1272 (D.C. 1988). See also Khaalis v. United States, 408 A.2d 313, 335 (D.C. 1979), cert. denied, 444 U.S. 1092, 100 S.Ct. 1059, 62 L.Ed.2d 781 (1980). However, the right to an appropriate voir dire is rooted in the Sixth Amendment guarantee of an impartial jury. Jenkins, supra, 541 A.2d at 1273 (citing Rosales-Lopez v. United States, 451 U.S. 182, 188, 101 S.Ct. 1629, 1634, 68 L.Ed.2d 22 (1981) (plurality opinion)). See also Dennis v. United States, 339 U.S. 162, 168, 70 S.Ct. 519, 521, 94 L.Ed. 734 (1950) (“the trial court has a serious duty to determine the question of actual bias”); Cordero v. United States, 456 A.2d 837, 847 (D.C. 1983) (quoting United States v. Dellinger, 472 F.2d 340, 367 (7th Cir. 1972), cert. denied, 410 U.S. 970, 93 S.Ct. 1443, 35 L.Ed.2d 706 (1973)) (adequate voir dire affords “a reasonable assurance that [juror] prejudice would be discovered if present”). Where, as here, dur*596ing voir dire, the government announces its intent to rely almost exclusively on police officer witnesses to attempt to prove its ease and several prospective jurors respond that either they or their family members are connected with law enforcement, the trial court, upon request by a defendant, must permit at least some minimal further inquiry which could elicit bias in favor of police testimony. Accord, Jenkins, supra, 541 A.2d at 1273 n. 1, 1275; Murray v. United States, 532 A.2d 120, 123-24 (D.C. 1987); Harvin v. United States, 297 A.2d 774, 777-78 (D.C. 1972).

In the present ease, the trial court initially, and quite appropriately, inquired of the venire members whether they were predisposed to lend more or less credence to police officer testimony. Harvin, supra, 297 A.2d at 777-78. Accord, Jenkins, supra, 541 A.2d at 1274-76; Brown v. United States, 119 U.S.App.D.C. 203, 204, 338 F.2d 543, 544 (1964); Sellers v. United States, 106 U.S.App.D.C. 209, 210, 271 F.2d 475, 476 (1959) (per curiam). Nevertheless, it is well settled that under circumstances similar to those in the present case, the trial court should not rely upon a single general question to prospective jurors to inquire about their potential bias. See Murray, supra, 532 A.2d at 123; Harvin, supra, 297 A.2d at 777-78; Dellinger, supra, 472 F.2d at 367. Further questioning is needed to permit parties “to explore the backgrounds and attitudes of the jurors to some extent in order to discover actual bias or cause.” Dellinger, supra, 472 F.2d at 367. See also Jenkins, supra, 541 A.2d at 1272 (quoting Glymph v. United States, 490 A.2d 1157, 1162 (D.C. 1985)). Here, the trial court’s failure to allow counsel to conduct any further voir dire whatever infringed upon the appellants’ right to exercise either challenges for cause or peremptory challenges.

The right of peremptory challenge is protected in the District of Columbia by statute, and, although this right is not specifically guaranteed by the Constitution, “[o]ne of the primary goals of peremptory challenges is to assure the trial’s impartiality.” Cash v. United States, 553 A.2d 215, 217 (D.C. 1989). See also Ross v. Oklahoma, 487 U.S. 81, 88, 108 S.Ct. 2273, 2278, 101 L.Ed.2d 80 (1988). “A defendant’s right to exclude any prospective juror by means of a peremptory challenge is ‘one of the most important of the rights secured to the accused_ Any system for the empanelling of a jury that pre[v]ents or embarrasses the full, unrestricted exercise by the accused of that right, must be condemned.’” Murray, supra, 532 A.2d at 125 (quoting Pointer v. United States, 151 U.S. 396, 408, 14 S.Ct. 410, 414, 38 L.Ed. 208 (1894)). “Hence, where the trial judge frustrates the defendant’s ‘effective use’ of peremptory challenges, the defendant need not demonstrate prejudice to obtain reversal of a conviction.” Wells v. United States, supra note 5, 515 A.2d at 1111.6 See also Wilson v. United States, 606 A.2d 1017, 1025 (D.C. 1992); (Lawrence) Williams v. United States, 552 A.2d 510, 512 (D.C. 1988). Although we can appreciate the trial court’s desire to proceed expeditiously, expe*597diency must always yield to a fair jury selection process.7

Accordingly, we hold that under the unique circumstances of this particular ease, the trial court, upon request, should have allowed, or conducted, a voir dire examination which was “minimally sufficient” under the standard set forth in Murray v. United States, supra, 532 A.2d at 123, in which this court condemned' the practice of asking “a single conclusory question regarding juror prejudice.” Id. (citing Dellinger, supra, 472 F.2d at 369). In Murray, the trial court asked whether any potential juror was closely associated with anyone having connections with law enforcement, and two prospective jurors responded affirmatively. After asking these particular panel members whether the affiliation would prejudice them in the case, the court asked follow-up questions. The trial court specifically asked one prospective juror, whose sister worked as a D.C. police officer, several detailed questions designed to elicit bias.

COURT: Is there anything about her work, maybe some story that she has told you of one of her experiences? Maybe she’s been injured or maybe she has shared a view with you that has made a strong impression upon you that causes you to believe that you might be biased or prejudice^] against either side in this case?

Id. at 121. The trial court also directed detailed inquiry to a prospective juror whose cousin was a lawyer. Id. at 123 n. 1.

In the present case, the court erred by denying defense counsel’s reasonable request for follow-up into one of the “common areas of inquiry in a jury voir dire.” Id. at 123 (citing Young v. United States, 478 A.2d 287, 289 (D.C. 1984)). Here, the trial court’s single conclusory question as to the venire’s ability to be impartial fell short of the minimal requirements set forth by this court in Murray. We conclude that the trial court did not meet the standards of minimal sufficiency in its questioning of the venire regarding potential bias. Accordingly, we reverse the convictions of Sykes and Gibson and remand their cases for new trials.8

So ordered.

dissenting:

We have often taken cognizance of the “broad discretion” of the trial judge in conducting voir dire to uncover possible juror biases, holding that reversal should occur only where “the record reveals an abuse of discretion coupled with substantial prejudice to the defendant.” Matthews v. United States, 599 A.2d 1389 (D.C. 1991) (quoting Boertje v. United States, 569 A.2d 586, 592 (D.C. 1989)). Here, the trial court first asked whether any jurors had any affiliation with law enforcement, and, with respect to the thirteen jurors who responded, questioned them individually as to the general nature of that affiliation. He followed that immediately with the general questions about favoring or disfavoring testimony by police officers.

Given our highly-deferential standard of review, I cannot say that the trial court under these particular circumstances was absolutely required to allow further inquiry at pain of reversal.1 Furthermore, appellants here made no showing whatever of any prej*598udice in fact or any analysis of the actual outcome of the jury selection process.2 I cannot agree that, in light of our repeated assertion of the need to show “substantial prejudice,” any limitation on voir dire can be treated as the equivalent of a direct interference with the exercise of the right to peremptory challenges and analyzed as such for purposes of reversal.3