A jury convicted appellant of possessing cocaine. D.C.Code § 33-541(d) (1988). He now appeals, contending the trial court erred by (1) refusing to allow two witnesses to testify on appellant’s behalf; (2) restricting his cross-examination of the arresting officer for alleged bias; and (3) allowing the prosecutor to misstate the law of actual and constructive possession in his closing argument. Appellant also contends that if none of these errors alone is enough for reversal, taken together they resulted in an unfair trial. Because we believe the trial court abused its discretion by applying an erroneous rule of relevance in refusing to allow one of the proffered defense witnesses to testify, we remand the case for a proper exercise of discretion.
I.
The police received a call from Monsen McConnell complaining of an armed man in her apartment. When Officers Savage and Taylor arrived at McConnell’s apartment, she met them at the door and told them that appellant was in the back room with a gun. The officers entered the apartment and told appellant to come to the front room. Some time later,1 appellant came out of the back room with his hands raised. The officers testified that they instructed appellant to put his hands on a kitchen table, which they previously observed had only books, and perhaps a satchel, on it. Officer Taylor frisked appellant while Officer Savage, standing on appellant’s left, watched. Officer Savage observed a small packet containing white rocks fall from appellant’s right side to the floor. While Officer Savage did not see the object fall from appellant’s jacket pocket, he assumed that it had come from the pocket because there was no other place from which the object could have fallen2 and appellant’s *491jacket pockets were turned inside-out. Officer Savage retrieved the package and arrested appellant for possession of cocaine.
II.
Appellant contends the trial court erred in refusing to allow two witnesses to testify on his behalf. According to appellant’s counsel, the first witness, Monsen McConnell, the tenant of the apartment where appellant was arrested, would have testified that there were no drugs on the table the day appellant was arrested. Appellant wished then to impeach McConnell by eliciting that she had routinely placed drugs on the table and that she had used cocaine frequently around the time appellant was arrested. The trial court questioned McConnell away from the jury. The court concluded that McConnell had a valid Fifth Amendment right to refuse to respond to the proffered questions and that, in any event, appellant could not impeach his own witness absent surprise.
Appellant claims the trial court erred on two grounds. First, he says, the court should have allowed him to question McConnell before the jury even if she asserted a Fifth Amendment privilege. Appellant contends that if the jury heard McConnell assert the privilege, his counsel could argue more convincingly, in closing, that her refusal to answer indicated that the cocaine was McConnell’s.
Appellant’s argument — as he readily admits — is foreclosed by the caselaw in this jurisdiction absent en banc review. See Bowles v. United States, 142 U.S.App.D.C. 26, 32, 439 F.2d 536, 542 (1970) (en banc) (“a witness should not be put on the stand for the purpose of having him [or her] exercise his [or her] privilege before the jury”), cert, denied, 401 U.S. 995, 91 S.Ct. 1240, 28 L.Ed.2d 533 (1971); see Davis v. United States, 482 A.2d 783, 785 (D.C.1984). We decline appellant’s invitation to urge the full court to reconsider the Bowles rule, for we believe it is sound.
Appellant next asserts that the trial court could have narrowed McConnell’s testimony and cross-examination in a way that permitted questioning her about unprivileged matters. According to appellant, he then could have used McConnell’s unprivileged testimony to support his version of the events surrounding appellant’s arrest— in particular, (1) as to the amount of time appellant stayed in the back room after the officers arrived (a fact bearing on his opportunity to dispose of the drugs), see supra note 1, and (2) as to whether children were in the room with appellant. The trial court refused to allow McConnell to testify, ruling that narrowing the scope of cross-examination would be unfair to the government.
The trial court erred in not permitting McConnell to testify on unprivileged material. The Fifth Amendment protects a citizen from testifying against herself, see Hoffman v. United States, 341 U.S. 479, 485-86, 71 S.Ct. 814, 817-18, 95 L.Ed. 1118 (1951), but when a witness asserts a Fifth Amendment privilege, she does not automatically disqualify herself from testifying. The trial court must determine whether the proposed testimony would tend to incriminate the witness and whether the risk of prosecution is “substantial and real.” daggers v. United States, 482 A.2d 786, 793 (D.C.1984); see Hoffman, 341 U.S. at 486, 71 S.Ct. at 818; Irby v. United States, 585 A.2d 759, 763 (D.C.1991). Normally the court does so by voir dire of the witness away from the jury. See Davis, 482 A.2d at 785. A witness’s privilege is narrower than a defendant’s. Salim v. United States, 480 A.2d 710, 714 (D.C.1984). It extends only to “specific questions; it does not encompass a refusal to take the stand at all.” Alston v. United States, 383 A.2d 307, 313 (D.C.1978); see Hoffman, 341 U.S. at 486, 71 S.Ct. at 818; Wilson v. United States, 558 A.2d 1135, 1141 (D.C.1989); Davis, 482 A.2d at 785; Salim, 480 A.2d at 714.
Based on this constitutional analysis, the trial court should have allowed McConnell to testify on the narrow, unprotected grounds requested: how long appellant remained in the back room before surrendering, and whether children were with him in the room at the time. The trial *492court could have effectively narrowed the scope of McConnell’s testimony and cross-examination to these unprivileged matters. We conclude, however, that the exclusion of McConnell’s testimony was harmless beyond a reasonable doubt. See Chapman v. California, 386 U.S. 18, 24, 87 S.Ct. 824, 828,17 L.Ed.2d 705 (1967); Davis, 482 A.2d at 786.3 First, on either version of the amount of time appellant spent in the back room, he had enough time to dispose of the drugs if he had chosen to do so. This is true because, according to appellant’s own testimony, he knew the police were coming seven to ten minutes before they arrived.4 Thus, appellant had at least seven minutes and fifteen seconds, if not twelve to fifteen minutes to dispose of the drugs. See supra notes 1 and 4. Because not even appellant’s own version of events helps his case, we can say beyond a reasonable doubt that the exclusion of McConnell’s testimony, which at best would have only corroborated appellant’s version, did not contribute to the verdict.
Second, whether or not there were children in the room with appellant was a fact too remote to have had any effect on the verdict; possession of cocaine. Chapman, 386 U.S. at 24, 87 S.Ct. at 828. The fact of children on the premises had not been mentioned on the radio call to Officers Savage and Taylor; the police were not responding to a report of “gun on children.” Nor is there any record basis for believing the officers otherwise knew children were with appellant before they arrived at McConnell’s apartment.5 Nor, finally, was appellant charged with an offense involving children. The fact that Officer Taylor did not recall whether children were present, therefore, was not remarkable. In any event, Officer Savage did remember the children. *493The only dispute between appellant’s and Savage’s testimony was the timing of the children’s exit from the back room.6 McConnell’s testimony would have served the limited purpose of challenging one government witness’s (Officer Taylor’s) recollection of events not directly pertinent to the charged offense. We are confident that beyond a reasonable doubt the exclusion of McConnell’s testimony did not contribute to the outcome.
III.
Appellant also contends the trial court erred in refusing to permit Maurice Lewis’s testimony for the defense. In an effort to create an impression that McConnell, not appellant, was responsible for the cocaine, defense counsel proffered at trial that Lewis would testify that McConnell had a cocaine habit and that Lewis frequently had seen drugs on McConnell’s table where appellant was frisked. Lewis, however, apparently could not testify that McConnell had left drugs on the table the day when appellant was arrested because Lewis had not been there that day. For this reason, the trial court ruled that Lewis’s testimony was inadmissible.7 We review for abuse of discretion. See Shepard v. United States, 538 A.2d 1115, 1116 (D.C.1988).
Due process and the Sixth Amendment right to compulsory process for obtaining witnesses entitled appellant to call witnesses on his own behalf. See Chambers v. Mississippi, 410 U.S. 284, 294, 93 S.Ct. 1038, 1045, 35 L.Ed.2d 297 (1973); King v. United States, 550 A.2d 348, 353 (D.C.1988). Accordingly, if Lewis had been able to testify that McConnell had a drug habit, that she had frequently (or even occasionally) kept cocaine on the table, and that cocaine was there as recently, for example, as a few weeks before appellant was arrested, that testimony could have been relevant to appellant’s defense that the cocaine which fell to the floor was not his. We therefore agree with appellant that the trial court erred in ruling that Lewis would not be allowed to testify simply because he could not place drugs on the *494table on the very day appellant was arrested.
There comes a point, however, at which such evidence becomes too attenuated to be of relevance; some temporal nexus between the witness’s observations and the crime is required. See Commonwealth v. Graziano, 368 Mass. 325, 329-30, 331 N.E.2d 808, 811 (1975) (“The evidence should not be too remote in time ... and it should be closely related to the facts of the case against the defendant.”). In this case, there was no defense proffer connecting Lewis’s observation of cocaine with appellant’s arrest. Counsel merely proffered that “on many, many occasions” Lewis had been in McConnell’s home he had “seen drugs on the table.” When the trial judge asked counsel to “[t]ell me something more specific ... ‘many, many times’ or ‘often’ is not helpful,” counsel could only reply “I’ll have to question Mr. Lewis.” Counsel should have known how recently Lewis could testify he had seen cocaine on McConnell’s table. In any event, appellant’s counsel was not justified in assuming the trial court would not have permitted her to question Lewis to elucidate the timing.8 Counsel did not ask to do so. Accordingly, counsel’s vague proffer stands as is, and there is no record basis for concluding that appellant could (or could not) have established a temporal nexus between Lewis’s observations and the crime. We therefore have a situation in which (1) the trial court erred in ruling that, for admissibility, Lewis would have to place cocaine on the table the day appellant was arrested, but in which (2) defense counsel did not proffer a clear enough time frame to permit us to ascertain whether the trial court, in the proper exercise of discretion, could or should have admitted the testimony. Despite counsel’s lack of tenacity, however, we conclude that the trial court’s error is significant enough to justify remanding the case for the trial court to decide, in the exercise of sound discretion, whether to admit Lewis’s testimony.
We reach this conclusion for two reasons. First, the trial court left defense counsel very little room to provide the appropriate proffer. See supra note 7. Second, the court had considerable leeway in allowing Lewis to testify even if Lewis only had seen cocaine on McConnell’s table weeks or perhaps even months before appellant's arrest. Such an attenuated connection could make the evidence marginally relevant at best, but not necessarily inadmissible. Lewis could have testified that McConnell had a drug habit and that Lewis had seen cocaine on McConnell’s table “on many, many occasions.” Because drug habits do not die easily, this proffer in itself came very close to demonstrating that the trial court, if properly applying the rule of relevance, should have taken a hard look before ruling the testimony inadmissible.9
Accordingly, we remand the case for the trial court to exercise proper discretion, based on a complete proffer, as to Lewis’s proposed testimony about seeing cocaine on McConnell’s table. See Wright v. United States, 508 A.2d 915, 919 (D.C.1986) (parties entitled to exercise of trial court discretion “unfettered by erroneous legal thinking”). If the court concludes that the testimony should have been admitted, the court *495shall order a new trial, for we cannot say the omission of relevant testimony about the source of the cocaine would be harmless. On the other hand, in the event the court rules Lewis’s testimony inadmissible, appellant’s conviction (absent other reversible error) shall stand affirmed — subject to the right to appeal the trial court’s ruling.
IV.
Appellant next contends the trial court erred in refusing to allow defense counsel to explore Officer Savage’s alleged bias; i.e., that Savage, in an attempt to fulfill his duty in the war on drugs, was biased in testifying about the cocaine falling from appellant. While it is undeniably true that litigants are given wide latitude to examine witnesses for alleged bias, Scull v. United States, 564 A.2d 1161, 1165 (D.C.1989), the bias must be grounded in a “well-reasoned suspicion” rather than “an improbable flight of fancy.” Id. at 1164 (citation and internal quotations omitted). Here, counsel provided no “ ‘facts which supported] a genuine belief’ that the witness [was] biased in the manner asserted.” Jones v. United States, 516 A.2d 513, 517 (D.C.1986) (quoting United States v. Fowler, 151 U.S.App.D.C. 79, 81, 465 F.2d 664, 666 (1972)). A general, broadstroke invocation of the “war on drugs” is insufficient to justify the requested cross-examination. See Van Ness v. United States, 568 A.2d 1079, 1082 (D.C.1990).10
V.
Appellant alleges, finally, that the prosecutor’s closing argument misstated the law on possession; that he kept from the jury the fact that guilt of the alleged charge hinged on a finding that the defendant knowingly and intentionally possessed illegal drugs; and that this omission — which was not raised at trial — amounted to plain error that clearly prejudiced appellant’s substantial rights. We perceive no error in the prosecutor’s statements, see Irick v. United States, 565 A.2d 26, 32 (D.C.1989), and, even if there was an error, appellant has not met the “heavy burden” that we have demanded for overturning the verdict. Watts v. United States, 362 A.2d 706, 709 (D.C.1976) (en banc); accord Allen v. United States, 495 A.2d 1145, 1152 (D.C.1985) (en banc).11
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For the reasons elaborated in Part III, we remand the case for further proceedings.
So Ordered.
. The precise time that appellant stayed in the room after the officers called to him is in dispute. The officers testified that the appellant came out after either fifteen or thirty seconds. Appellant testified that he left the room four or five minutes later.
. Appellant argues that someone else placed the packet on the table and that he may have knocked it off unwittingly during the frisk.
. The trial court also refused to allow McConnell to testify for the defense, as a hostile witness, because she would have testified only for impeachment purposes and appellant could not claim prejudicial surprise. See Beale v. United. States, 465 A.2d 796, 802 (D.C.1983), cert. denied, 465 U.S. 1030, 104 S.Ct. 1293, 79 L.Ed.2d 694 (1984); Scott v. United States, 412 A.2d 364, 367-68 (D.C.1980); D.C.Code § 14-102 (1989). Arguably, appellant proffered McConnell’s testimony not to bolster his defense as such but merely to impeach the police officers’ testimony, in which case the issues of hostile witness and surprise might not have arisen unless McConnell had testified differently from the testimony as proffered. Accordingly, we assume for the sake of argument that the trial court erred in this ruling, as well as on the Fifth Amendment issue, and address the issue of harmless error.
We also assume, without deciding, that the error here should be judged under the constitutional standard of Chapman, 386 U.S. at 24, 87 S.Ct. at 828, because even under that test we find the error harmless.
. Appellant testified that McConnell came back to the apartment after calling the police and told him that the police were coming. The police arrived, according to appellant, seven to ten minutes later. This testimony is substantiated by Officer Savage, who stated that he and Officer Taylor arrived at the apartment "five to ten minutes” after they received the radio call.
Judge Schwelb writes: "If Ms. McConnell had confirmed that Collins waited several minutes before he emerged and that he did not come out immediately, as the officers testified he did, then this would have provided him with a 'common sense’ argument against the notion that it was he who possessed the packet of cocaine.” Post at 501. Given appellant’s admission that he knew the police were coming seven to ten minutes before they arrived, we do not believe testimony from McConnell that appellant had been in the back room another four or five minutes would have convinced a "common sense” jury that appellant — because of the extra time— would have been able to dispose of cocaine that otherwise would have remained in his pocket.
.Our dissenting colleague asserts that the officers responded to a "situation in which children [were] in apparent danger from a man who reportedly ha[d] a gun and who refuse[d] for some period of time either to free the children or to surrender,” and that "for several minutes, two young lives appeared to be hanging in the balance." Post at 501-502. It is true that appellant himself testified that one of the officers asked, "Why don’t you send the children out front?” when appellant remained in the back room after the officer had asked him to come out. But appellant has never proffered that McConnell would have corroborated this testimony. According to the proffer, McConnell merely would have confirmed that children (apparently her own) were in the back room with appellant four or five minutes after the police arrived. See supra note 1. Moreover, there is no indication from appellant’s proffer that McConnell was ever concerned about her children’s safety. In short, except for appellant's own testimony, there is no record or proffered basis for believing that the children’s safety was at issue.
. Officer Savage testified that appellant came out of the back room followed by the children. Because he was focusing on appellant, however, he did not "recall exactly when the children came out.” Appellant testified that he had sent the children out before he left the back room.
. We construe the trial court’s remarks in the light most favorable to appellant. The court properly was concerned that, for admissibility, the Lewis testimony would have to permit the jury to draw a reasonable inference that cocaine was on McConnell’s table on the day appellant was arrested. At the time Lewis's testimony was proffered, however, the court did not conclusively rule that the Lewis evidence would be inadmissible for that purpose unless Lewis could put cocaine on McConnell’s table on the very day of appellant’s arrest. Coimsel still could have argued that Lewis’s testimony was relevant even if it pertained only to an earlier day that was close enough to the day of arrest to support the contention that cocaine was also likely to have been on the table when appellant was arrested. Near the beginning of the hearing, the court asked, ”[W]ill your client [meaning Lewis] be testifying that he that day saw drugs or knew there were drugs on the table?” Then a few moments later the court asked with respect to Lewis’s testimony, whether he would say that "somehow [the drugs] were there that day and had been there sometime before?” Nineteen pages of transcript later, the court concluded: "You have nothing to link [Lewis’s testimony] for that particular day [of appellant’s arrest]. I think it is very speculative to say, either your client or anybody who has known Mr. Lewis, can say there were drugs on the table or in the apartment on the day in question of the incident.” These statements showed the court’s proper concern that the proffered evidence must be linked to the time of appellant’s arrest, but the court’s comments did not necessarily foreclose counsel from tendering testimony by Lewis that he had seen cocaine on McConnell’s table near, but not on, the day of arrest. Counsel did not do so. The court ruled Lewis could not testify. When court and counsel later discussed McConnell’s proffered testimony, however, the court broadened its position, indicating that only evidence directly placing cocaine on McConnell’s table on the day of arrest would be relevant: "It makes no difference whether there were drugs the day before or whatever else. The only question is whether there were any drugs on the table that particular day. Okay. That’s the only thing that’s pertinent. What happened on prior occasions doesn’t make one bit of difference.” This statement, made in the context of McConnell’s proposed testimony, was understandable because McConnell, as occupant of the premises, presumably could testify whether cocaine was on the table that day.
. Court and counsel had just begun to explore the relevance of the Lewis testimony when counsel told the court that she would have to question Lewis before she could proffer how often he had seen cocaine on McConnell’s table. At that time, the trial court had not clearly indicated that, for admissibility, Lewis’s testimony would have to show Lewis had seen cocaine at McConnell’s on the day of appellant’s arrest. See supra note 7. Thus, there is no reason to believe, as our dissenting colleague does, that the trial court’s "remarks would have made any inquiry into the precise dates of Lewis’ visits to the McConnell residence appear futile.” Post at 498.
. We learned from appellant’s counsel at oral argument on appeal that the latest Lewis could have testified he had seen drugs on McConnell’s table was in January 1988, four to five months before appellant’s arrest on June 3, 1988. On remand, if this continues to be appellant’s proffer, the trial court will have to determine whether testimony would, or would not, be "too remote in time," Graziano, 368 Mass, at 329-30, 331 N.E.2d at 811, to be relevant. We cannot say at this time, as a matter of law, that the trial court would have abused its discretion in admitting such evidence.
. Even if appellant were correct — that the trial court inappropriately limited the cross-examination — the exclusion was clearly harmless beyond a reasonable doubt. See Delaware v. Van Arsdall, 475 U.S. 673, 684, 106 S.Ct. 1431, 1438, 89 L.Ed.2d 674 (1986); Brooks v. United States, 516 A.2d 913, 916 (D.C.1986). Appellant’s proposed questioning would not have significantly contributed to the existing evidence, which was sufficient for the jury to infer the type of bias appellant was asserting.
. Appellant also asserts that the totality of the excluded evidence resulted in an unfair trial. The only possible error of this kind was the denial of McConnell's testimony about the time appellant spent in the back room after the police arrived and about when children came out of that room. Any such error was harmless. See supra Part II. The other evidence properly excluded cannot result in reversible error.