I
THE CASE
These consolidated appeals arise out of the shooting and wounding of an undercover police officer who was investigating illicit drug activity and attempting to make an arrest. Following a five-week jury trial, the appellants Larry Daniels (L.D.), his brother Jerry Daniels (J.D.)1 and Curtis Irick were all convicted of possession of cocaine with intent to distribute it (PWID), in violation of D.C.Code § 33-541(a)(l) (1988). J.D. and Irick were also convicted of assault on a police officer while armed, § 22-505(a) and (b), and of carrying a pistol without a license, § 22-3204. All three appellants were sentenced to serve mandatory minimum prison terms for PWID, and J.D. and Irick received substantial additional periods of incarceration on the assault and weapons counts. •*-
On appeal, L.D. claims that the evidence against him was insufficient to support his conviction. J.D. contends that the trial judge abused his discretion by improperly admitting certain testimony by the prosecution’s expert witness. Both Irick and J.D. seek reversal of their convictions on the grounds of alleged prosecutorial misconduct.
With respect to L.D.’s appeal, we hold that the evidence against him, when viewed as it must be in the light most favorable to the government, was sufficient to support his conviction. We also discern no abuse of discretion in the trial judge’s admission of the expert testimony challenged by J.D.
The issue of prosecutorial misconduct is more difficult. We agree with Irick and J.D. that on some occasions the conduct of the prosecutor, who apparently threatened outside the courtroom to “bust [J.D.’s counsel] in the mouth,” was less than a model of decorum. A few comments made by the prosecutor during the trial were plainly inappropriate, and a number of others were close to the line and, from the calm and detached perspective of appellate review, might better have been left unsaid. Some of what the prosecutor did was triggered but, we emphasize, not excused, by some troubling tactics by J.D.’s counsel. On balance, we cannot agree with J.D. and *28Irick that the prosecutor’s conduct was “unprovoked” or “egregious.” Indeed, we note that much (though not all) of the alleged misconduct passed without objection by any of the three defense attorneys and is challenged for the first time on appeal. Appellants were not entitled to a perfect trial, and we are satisfied that they received a fair one. Accordingly, we affirm their convictions.
II
THE FACTS2
A. The prosecution case
The prosecution introduced evidence tending to show that on January 9, 1986, Officers Jimmie Lewis and Byron Wallace were in casual clothes, assigned to enforcement of the drug laws. Between 6:15 and 6:30 p.m., they monitored a broadcast for subjects selling drugs at a nearby playground. They drove to the area, and eventually saw a group of men near the door to a school building. The officers walked in the direction of the group, and Wallace inquired if “anybody got halves [of cocaine].” A man later identified as L.D. approached the officers. He said that he had halves for fifty dollars and asked for the money. Officer Wallace, however, had seen a man later identified as J.D. some 25 to 30 feet away actually delivering drugs. He told L.D. that he would go straight to the man with the dope. The officers walked towards J.D.
J.D., with his hand still in a pouch apparently filled with the cocaine which he was selling, asked Officer Wallace “what do you need?” Wallace identified himself as a police officer and told J.D. that he was under arrest. J.D. offered no resistance and sat on the ground. Officer Lewis prepared to call for a transportation unit over the police radio, but there was “chatter” on the channel which he intended to use.
As Officer Lewis was waiting for the channel to clear, a tall man, later identified as Irick, approached the group, carrying a large handgun. Wallace told Irick that he and Lewis were police officers. J.D. still seated on the ground, told Irick: “Get them, Boo [or Butch].... Don’t let them get me. Shoot them. Don’t let them take me,” or words to that effect. Lewis began to reach for his service revolver. Irick pointed his weapon at Lewis and fired from a distance of five feet. The bullet struck Lewis’ thumb and body, missed vital organs in his abdomen, and exited some three millimeters from his spine. Irick and J.D. fled. Officer Wallace gave chase, and he and Officer Lewis both fired shots in the fugitives’ direction. Wallace then returned to obtain assistance for his wounded colleague. A civilian witness testified that he saw two men running from the scene, and that he heard one of them say that he had “got that motherfucker.”
More police officers came to the scene. They found a Wendy’s bag with a warm hamburger, as well as three packets of cocaine, at the location where J.D. had been standing. J.D.’s fingerprints were on the Wendy’s bag.
Shortly after the shooting, Officer William Herndon responded to the area. He saw L.D. jump over a fence and walk away at a rapid pace. L.D.’s clothing matched the description of that worn by one of the drug sellers in the original radio lookout. Officer Herndon ordered L.D. to stop. L.D. volunteered, for no readily apparent reason, that he had just got out of a cab. No cab was in sight.
Cassandra Dorsey, a long term heroin and cocaine addict who was facing possible revocation of her probation, also testified for the prosecution. At the time of the offenses, she was living with her boyfriend Tommy Daniels, a brother of J.D. and L.D., and with the Daniels brothers’ mother. She testified that J.D., Irick and a third man arrived at the house between 6 and 7 p.m. on the day of the shooting. The men talked about having shot a police officer, and Irick suggested that they had better get out of town. Irick gave a large gun to J.D., who passed it on to his brother Tom*29my with directions to bury it. Based on information received from Ms. Dorsey and Tommy Daniels, police eventually recovered the hand gun under a van behind the garage near the Daniels’ home. The bullet that passed through Officer Lewis was positively identified as having come from this handgun.
Detective Johnny St. Valentine Brown testified as an expert witness for the government, primarily on the subject of the modus operandi of drug dealers. He related, among other things, that more sophisticated drug distribution units may include a “lieutenant” or “enforcer.” This individual’s job is to be on the scene of the distribution activity, armed with a weapon, to protect the individuals engaged in the sale of the drugs from “stick-up boys” and police.3 He testified that if individuals who are close to each other in the same location are distributing drugs, they are likely to be part of the same organization.
B. The defense case
L.D.’s defense was a general denial, and he called no witnesses. J.D. likewise did not testify. Through counsel, he admitted his guilt of the PWID charge, but vigorously contested the assault and weapons charges. In doing so, he relied on the evidence presented by his codefendant Irick.
Irick testified in substance that he had come to the playground to buy cocaine from J.D., whom he knew only slightly, having purchased drugs from him on a previous occasion at a different location. He denied being associated in any drug selling operation with J.D. or anyone else. On his way to make the purchase, he picked up a .44 caliber handgun at his father’s garage for the purpose of taking it to his mother’s home. Upon his arrival at the playground, he gave J.D. $45.00, and J.D. asked him to wait a few minutes so that he could procure a “half” of cocaine for him.
While he was awaiting the arrival of the cocaine, he witnessed two men apparently attempting to rob J.D. at gunpoint. Concerned because J.D. had his $45.00, Irick pulled out his weapon and ordered one of the men — who later turned out to be Officer Wallace — to drop his gun and raise his hands. The other man who, unbeknownst to Irick, was Officer Lewis, began to pull out his revolver and appeared to be about to shoot Irick. Irick then shot Lewis in the hand. After some further shooting, Irick and J.D. fled. Irick went to J.D.’s house because J.D. had his money. Neither of the two apparent robbers announced that he was a police officer,4 and Irick only learned of his victim’s identity from J.D.’s brother Tommy, who had heard it on a television news report.5
Ill
L.D.’S APPEAL
L.D. contends that the evidence was insufficient to establish beyond a reasonable doubt that he aided and abetted the possession of cocaine with intent to distribute it.6 Although the case against him was perhaps less than overwhelming, we cannot *30agree that it was inadequate to support the jury’s verdict.
In evaluating a claim of insufficiency, we must consider the evidence in the light most favorable to the government, giving the prosecutor the benefit of all reasonable inferences from the evidence. Patterson v. United States, 479 A.2d 335, 337-38 (D.C.1984). Neither this court nor the trial court may usurp the jury’s prerogative of determining credibility, weighing the evidence, and drawing reasonable inferences. Stack v. United States, 519 A.2d 147, 159-60 (D.C.1986).
The evidence against L.D., all of which was uncontradicted, included the following:
(1) L.D. offered to sell cocaine to the officers;
(2) his brother, J.D., with whom the jury could reasonably presume that he was acquainted, was 25 to 30 feet away, selling cocaine out of a pouch;
(3) Detective Brown testified that street distribution units of illicit drugs often contain a “runner” or “juggler” who advertises the product for sale, and that individuals who sell drugs in close proximity to one another are ordinarily part of the same unit;
(4) L.D. climbed a fence to make a moderately hurried7 exit and lied to the police 8 about where he had been.
L.D. argues on appeal that brothers cannot be presumed to act in concert, noting among other examples of “sibling rivalry” that Cain slew Abel and subsequently denied knowledge of the offense and that Billy the Kid’s brother “set him up for his death.” We agree that guilt by association is a very dangerous principle, and that inferring culpability from an accused’s blood relationship to a wrongdoer is likewise fraught with peril.9
In the present case, however, L.D. in effect asks us to rule as a matter of law that it must have been a coincidence10 that L.D. was advertising the very drug which his brother was selling 25 to 30 feet away, and that the jury could not legitimately infer collaboration between them beyond a reasonable doubt. Coincidences do happen but, especially in the light of Detective Brown’s testimony, the jury was not required to believe it to be fortuitous that the two brothers were engaged in the activities disclosed in this record at the same time and in almost the same place.
L.D. argues that, as Detective Brown acknowledged, people who purport to negotiate drug deals often have no intention of selling drugs, but are merely out to steal the would-be purchaser’s money. Moreover, it is conceivable that L.D., if he did propose to provide cocaine to the officers, might have secured it from someone other than his brother. These hypotheses, while not exactly complimentary to L.D., are consistent with innocence of this particular charge.
It is well settled, however, that the government’s evidence may be sufficient to survive a motion for judgment of acquittal even if it does not exclude every reasonable hypothesis other than guilt. Holland v. United States, 348 U.S. 121, 139-40, 75 *31S.Ct. 127, 137-38, 99 L.Ed. 150 (1954); Chaconas v. United States, 326 A.2d 792, 798 (D.C.1974). The evidence, in other words, need not compel a finding of guilt beyond a reasonable doubt. Curry v. United States, 520 A.2d 255, 263 (D.C.1987) (emphasis added). In the present ease, the jury was not required, in order to convict L.D., to “cross the bounds of permissible inference and enter the forbidden territory of conjecture and speculation.” Id. Accordingly, L.D.’s conviction must be affirmed.11
IV
THE EXPERT TESTIMONY
Over defense objection, the trial judge permitted Detective Brown to testify with respect to the role of an “enforcer” in a drug organization. As previously noted, the judge struck Brown’s testimony that other members of the distribution unit would be aware of the enforcer’s presence. We hold that the judge exercised his discretion judiciously and that there was no error.
J.D. contends that the evidence was improperly admitted because the question whether he and Irick were working in concert was well within the “ken” of lay jurors, and thus not an appropriate subject of expert testimony. Cf. Dyas v. United States, 376 A.2d 827, 832 (D.C.), cert. denied, 434 U.S. 973, 98 S.Ct. 529, 54 L.Ed.2d 464 (1977). In our view, however, jurors unfamiliar with illicit drug operations could be aided in their search for the truth by expert testimony which casts some light on the kind of relationship that is likely to exist, on the streets of this city, between a drug seller who has been placed under arrest and a gunman who comes to his assistance. Although the average reader of the daily press might well surmise, to quote Detective Brown, that “when you relate to drugs and guns it’s like a marriage,” it was surely reasonable for the trial judge to conclude that an expert’s explication of the background of this melancholy proposition would be helpful to the jury.
“The trial court has broad discretion to admit or exclude expert testimony, and its decision either way will not be disturbed on appeal unless it is manifestly erroneous.” Hinnant v. United States, 520 A.2d 292, 293 (D.C.1987). Since the modus operandi of drug traffickers is not within the ken of the average lay person, expert testimony on the subject may be admitted if relevant. Id.12 We think Hinnant controls this case, and find no abuse of discretion. Accord, United States v. Dunn, 269 U.S.App.D.C. 373, 375, 846 F.2d 761, 763 (1988); see also United States v. Resto, 824 F.2d 210, 212 (2d Cir.1987) (testimony as to role of a “steerer,” apparently the New York equivalent of a “runner” or “juggler”).
V
ALLEGED PROSECUTORIAL MISCONDUCT
J.D. and Irick claim that each was denied a fair trial as a result of prosecutorial misconduct. They contend primarily that the prosecutor attacked the integrity of defense counsel, expressed his personal opinion as to the veracity of witnesses, argued facts not in evidence, and depicted appellants as members of a sinister drug organization. The government denies that the prosecutor’s actions constituted misconduct, noting that there was no objection in the trial court to much of the conduct challenged on appeal, and arguing that in general the prosecutor responded temperately to alleged improprieties by J.D.’s counsel. *32In the alternative, the government contends that even if this court were to find that improprieties occurred, the convictions should not be reversed in light of the strength of the government’s case. We agree that, taking the record as a whole, reversal is not appropriate.
A. The legal standard
In evaluating appellants’ contentions, we must first determine whether the prosecutor’s comments constituted misconduct. Hammill v. United States, 498 A.2d 551, 554 (D.C.1985); Sherrod v. United States, 478 A.2d 644, 655 (D.C.1984). If misconduct has occurred, then, viewing the comments in context, we must consider the gravity of the misconduct, its relationship to the issue of guilt, the effect of any corrective action by the trial judge, and the strength of the government’s case. Hammill, supra, 498 A.2d at 554. Where a defendant has properly preserved his objections, the court must determine
whether we can say with fair assurance, after all that has happened without stripping the erroneous action from the whole, that the judgment was not substantially swayed by the error.
(Philip) Dyson v. United States, 418 A.2d 127, 132 (D.C.1980); Hammill, supra, 498 A.2d at 554. Where the defendant failed to object, on the other hand,13 we will reverse his conviction only if the misconduct so clearly prejudiced his substantial rights as to jeopardize the fairness and integrity of his trial. Sherrod, supra, 478 A.2d at 655; Watts v. United States, 362 A.2d 706, 709 (D.C.1976) (en banc). The Supreme Court has cautioned that reversal for plain error in cases of alleged prosecutorial miseon-duct should be confined to “particularly egregious” situations. United States v. Young, 470 U.S. 1, 15, 105 S.Ct. 1038, 1046, 84 L.Ed.2d 1 (1985).
We must also be cognizant of the fact that perfection is a rare commodity, that mistakes and misjudgments are likely to occur during long and hotly contested litigation, and that if every conviction following an imperfect trial were set aside, a judicial process run by mere mortals would soon run aground. The Supreme Court warned in Young that a criminal conviction “is not to be lightly overturned on the basis of a prosecutor’s comments standing alone, for the statements must be viewed in context.” Id. at 11, 105 S.Ct. at 1044.14
We must also bear in mind that our assessment of the dynamics of a trial is limited to what can be discerned from a cold record. As this court recognized in Smith v. United States, 315 A.2d 163, 167 (D.C.), cert. denied, 419 U.S. 896, 95 S.Ct. 174, 42 L.Ed.2d 139 (1974):
It is peculiarly within the knowledge of the trial judge whether remarks of counsel during the trial tend to prejudice the cause of a party. The courtroom atmosphere, prior remarks which have provoked the questioned statements, and other factors which cannot be appraised by a reviewing court may render remarks of counsel innocuous, although they may appear viciously prejudicial when removed from their setting.15
See also Sherrod, supra, 478 A.2d at 658 n. 17; Sherer v. United States, 470 A.2d 732, 743 (D.C.1983), cert. denied, 469 U.S. 931, 105 S.Ct. 325, 83 L.Ed.2d 262 (1984) (court attached “considerable significance” *33to trial judge’s denial of mistrial following “heated” and improper arguments of attorneys).
Finally, we emphasize that although appellants’ complaint is primarily with the prosecutor, it is our function to review the record for legal error or abuse of discretion by the trial judge, not by counsel. Such error or abuse may, to be sure, embrace not only incorrect rulings but also, on occasion, failure to intervene sua sponte when such intervention is called for, United States v. Jenkins, 140 U.S.App.D.C. 392, 397, 436 F.2d 140, 145 (1970), or to react with sufficient promptness and vigor to prosecutorial misdeeds. King v. United States, 125 U.S.App.D.C. 318, 330-31, 372 F.2d 383, 395-96 (1967). Nevertheless, absent some improper ruling or omission by the trial judge, we cannot ordinarily16 reverse a conviction, and our ultimate focus must therefore be on what the judge did or failed to do.
With these principles in mind, we address appellants’ principal contentions in turn.
B. “Attacking the integrity of defense counsel ”
During his cross-examination of Cassandra Dorsey, J.D.’s counsel inquired, in the presence of the jury, whether the prosecutor had threatened her with imprisonment in order to secure from her testimony favorable to the government. Although Ms. Dorsey responded firmly in the negative,17 and no contrary evidence was adduced, the prosecutor took personal offense, and it was this incident that triggered his apparent threat (in the courthouse but outside the presence of the jury) to bust his astonished adversary in the mouth. The trial judge denounced the questioning as “absolutely scurrilous” and “outrageous,” and criticized J.D.’s counsel for slandering “one of the most highly ethical Assistant United States Attorneys” the judge had ever dealt with. Although the judge later tempered his criticism of the defense attorney,18 there can be little doubt that the tensions generated by the incident affected the future course of the trial.
Early in his rebuttal argument, the prosecutor complained that it was his “thankless task to be slandered and accused of misconduct.” Citing chapter and verse for the proposition that the government had the evidence, including the gun, the drugs, and the bullet, he inquired rhetorically:
So what else can they do? Let’s say [the prosecutor] is manipulating the truth. Well, this is a case about character. And I value my character.
He went on to state:
What else do we know about the manipulators of truth in this courtroom? They slandered the Government back and forth like a ping-pong ball in the last five weeks.
In denying a mistrial, the trial judge ruled that these remarks were directed at J.D. and Irick, and that he (the judge) did not think the prosecutor had deliberately attempted to impute any improper motives to counsel. See Donnelly v. DeChristoforo, 416 U.S. 637, 643-44, 94 S.Ct. 1868, 1871-72, 40 L.Ed.2d 431 (1974) (court should not attach the most sinister possible interpretation to the prosecutor’s remarks).19 Although there was some ambi*34guity in what the prosecutor said,20 we are satisfied that, in context, his remarks would have been understood as having been directed at the defendants and not to J.D.’s counsel, and that in comparison with J.D.’s attorney, the prosecutor, though perhaps prone to use invective, was, if anything, more sinned against than sinning.
The prosecutor also remarked that defense counsel “sandbagged” Officer Lewis by adducing testimony that Irick believed that the two officers were armed robbers without interrogating Lewis on the subject. We find the use of the word “sandbagged” ill-chosen, especially since the prosecutor could have recalled Officer Lewis to the witness stand but did not do so.21 There was no objection, however;22 if there had been, the trial judge could have taken corrective action proportionate to the use of the ill-chosen epithet.
Ad hominem attacks against opposing counsel are uncalled for and unprofessional. Sherer v. United States, supra, 470 A.2d at 742; see also Mathis v. United States, 513 A.2d 1344, 1347 (D.C.1986). The prosecutor would have done better to “keep his cool,” to choose his words more carefully, and to identify more precisely those to whom he was attributing mischief, distinguishing more clearly between defendants and their counsel, as well as between the individual attorneys. We cannot agree with appellants, however, that his remarks were egregious, or that in context they had any significant potential for affecting the verdict.
C. “Expressing personal opinions regarding the credibility of witnesses”
Irick and J.D. contend that the prosecutor improperly vouched for the credibility of his witnesses and denigrated that of Irick. We hold that with one relatively minor exception relating to a peripheral *35issue23 the prosecutor’s remarks on these matters were permissible comments on the evidence. The trial judge applied correct legal standards and committed no reversible error in failing to intervene sua sponte where no objection was made or in his denial of motions for a mistrial.
Defending Cassandra Dorsey’s veracity, which had come under heavy attack during cross-examination, the prosecutor argued that she had demonstrated “character” and merited admiration by her willingness to testify for the government. He noted that she acknowledged her addiction and risked the enmity of the Daniels family, with whom she lived, and that it showed courage to come in and say, in effect, that “it’s wrong to shoot a cop and that’s why I’m here.” None of the defense attorneys ever objected to these remarks, which were made primarily during the prosecutor’s initial closing argument. The prosecutor was doing no more than drawing a reasonable inference from the evidence, and there was no reason for the judge to inject himself into the matter without being asked to do so.
Appellants also contend that the judge should have declared a mistrial because the prosecutor allegedly characterized Irick as a liar, primarily by referring to him sarcastically as Irick “the truthteller” and by stating or implying in other ways that he was not telling the truth. The context of these comments reveals that all but those relating to Irick’s employment and residence were made in connection with descriptions of evidence contrary to that of Irick. They were generally coupled with an invitation to the jurors to believe other witnesses and to discredit Iriek’s testimony, either directly or in the form of a rhetorical question. The trial judge denied mistrial motions because the prosecutor
is certainly entitled to comment on the credibility of Mr. Irick_ The Court of Appeals may some day say that sarcastically referring to a witness as a truth teller is the same kind of arguably improper argument as calling a witness a liar, which I never thought was improper until the Court of Appeals said so. I don’t think the Court of Appeals has said that yet and I don’t think the argument was in any way improper....
We agree with the trial judge’s analysis.24
Despite decisions in the dozens, the law governing what a prosecutor may or may not say about the credibility of a testifying defendant or defense witness is not always easy to discern or apply. On the one hand, “this court has repeatedly condemned assertions by counsel that a witness had lied on the witness stand.” Jones v. United States, 512 A.2d 253, 257 (D.C.1986). “It is for the jury to decide whether a witness is truthful, and an attorney may not inject personal evaluations and opinions as to the witness’ veracity.” (Philip) Dyson v. United States, 418 A.2d 127, 130 (D.C.1980); Jones, supra, 512 A.2d at 257.25 Characterization of defense testimony as incredible is permissible, on the other hand, “when it is a logical inference from the evidence, and not merely the prosecutor’s personal opinion as to appellant’s veracity.” Hammill v. United States, 498 A.2d 551, 557 (D.C.1985). Indeed, “characterizing testimony as incredible is an accepted and proper form of comment on contradictory testimony.” (Philip) Dyson, supra, 418 A.2d at 130. In Kleinbart v. United *36States, 426 A.2d 343, 352 (D.C.1981), this court held that it was acceptable for the prosecutor to call defense testimony “suspicious” and “perjured,” and to claim that the defendant “conjured up witnesses [who] ... lied to you,” where there was a basis in the evidence for these charges.
Although it may be difficult to reconcile the results in these cases with one another, they all support the proposition that the key inquiry is whether the attorney is commenting on the evidence, which he may do, or expressing a personal opinion, which is taboo. A comment will be within the acceptable range as long as it is in the general nature of argument, and not an outright expression of opinion. Logan v. United States, 489 A.2d 485, 490-91 (D.C.1985); Arnold v. United States, 467 A.2d 136, 138 n. 2 (D.C.1983) (per curiam).26
In the present case, the prosecutor expressly stated to the jurors, both in his initial closing argument and in rebuttal, that he was not claiming that anyone was lying, and that it was their responsibility to decide where the truth lay.27 As stated above, the remarks of which appellants complain were sufficiently tied in to the discussion of the evidence to avoid any suggestion that the prosecutor was in effect adding his own unsworn testimony28 to the evidence in the record. His recitation that the jury must decide issues of credibility, together with the judge’s instructions to the same effect, made it unlikely that the jurors were misled or that they convicted appellants for improper reasons.
Reasonable people may differ about the appropriateness of the prosecutor’s apparent sarcasm in referring to Irick as a “truthteller.” “It should not be necessary to explain ... that sarcasm and ridicule are not the stuff of good argument or good taste in judicial proceedings. When the government resorts to such behavior, we are the poorer for it.” Carter v. United States, 141 U.S.App.D.C. 259, 261, 437 F.2d 692, 694 (1970), cert. denied, 402 U.S. 912, 91 S.Ct. 1393, 28 L.Ed.2d 655 (1971). The prosecutor may, on the other hand, prosecute “with earnestness and vigor.” Berger v. United States, 295 U.S. 78, 88, 55 S.Ct. 629, 633, 79 L.Ed. 1314 (1935); Young, supra, 470 U.S. at 7, 105 S.Ct. at 1042. Just as he need not sanitize the government’s evidence or cleanse it of its emotional impact, Powell v. United States, 485 A.2d 596, 599 (D.C.1984), cert. denied, 474 U.S. 981, 106 S.Ct. 420, 88 L.Ed.2d 339 (1985), so too he is not required to articulate his arguments in a dreary monotone stripped of all emphasis, spirit, or indignation. Cf. Mathis v. United States, 513 A.2d 1344, 1348 n. 10 (D.C.1986). A prosecutor “certainly is free to strike hard blows at witnesses whose credibility he is challenging.” Harris v. United States, 131 U.S.App.D.C. 105, 108, 402 F.2d 656, 659 (1968). Although name-calling is out of *37bounds, a bland presentation robs the adversary system of the life and zest which are needed to capture and retain the jury’s attention and ensure an interested and informed search for the truth. The Constitution does not require prosecutors to be boring.
There was extensive evidence in the record to support the contention that Irick was lying,29 and we agree with the trial judge that the prosecutor’s tactics in regard to Irick’s credibility did not exceed the bounds of propriety.
D. “Arguing facts not in evidence”
Officer Wallace testified that when Irick approached the scene, gun drawn, J.D., still on the ground, said:
Get them Boo [or Butch]. Don’t let them take me. Shoot them. Don’t let them take me.
In his initial closing argument, the prosecutor described the event in the following manner:
Jerry is doing what he knows Curtis is paid to do. He’s letting him know now’s the time Curtis, get ’em off me. I don’t want to go to jail for selling dope. They ain’t got their guns out then, I’m not going to be caught in the cross fire. You get them off me.
A few minutes later, the prosecutor addressed Irick’s state of mind:
Isn’t that the mind of a man who wanted to kill that night? Running with his business partner. Who knew, as Detective Brown told you, that Curtis Irick was out there for one purpose and that’s to have a pistol to protect him.
(Emphasis added.) In fact, the trial judge had stricken Detective Brown’s testimony that the other members of the distribution unit would know that the enforcer was there to protect them.
No objection was made by any of the defense counsel to either of these passages in the prosecutor’s argument, nor did any defendant seek a mistrial on the basis of either comment. We must therefore decide whether the trial judge committed plain error by failing to intervene sua sponte. We are satisfied that he did not.
Appellants argued that the prosecutor, by adding the words “I don’t want to go to jail for selling dope” to Officer Wallace’s description of J.D.’s remarks, effectively created evidence that J.D. knew that Lewis and Wallace were police officers. Whether the officers had identified themselves as police, and whether appellants knew that they were officers, was a major factual issue in the case. The government responds that the prosecutor was simply drawing reasonable inferences about J.D.’s state of mind, based on what J.D. said and other evidence of collaboration between him and Irick. The precise words used by the prosecutor could reasonably be construed either as describing what J.D. said (in which case they would be improper)30 or as arguing what he was probably thinking (in which case the inference being drawn from all of the evidence would, in our view, be reasonable).
Greater precision on the prosecutor’s part would undoubtedly have been helpful to the jury. As it was, however, defense counsel had the opportunity to address the alleged misstatement in their closing arguments, and perhaps to “score points” with *38the jury by demonstrating the prosecutor’s inaccuracy or imprecision. The trial judge instructed the jurors that their recollection of the evidence controls, and we do not think that the comments in question warrant reversal.
Turning to the prosecutor’s infelicitous allusion to what Detective Brown had said, it was undoubtedly inappropriate to predicate an argument that J.D. knew that Irick was there to protect him on the detective’s stricken testimony. Although the government correctly claims that there was ample basis in the record to support an inference that J.D. knew that Irick was there and why, this does not excuse the improper recitation of testimony which was not in the record in support of a hotly disputed proposition.
An objection to this mischaracterization of the evidence might well have resulted in a firm correction by the trial judge, who had previously ruled on the relevant legal question in appellants’ favor. This was, however, hardly a situation so extreme that it required or even warranted intervention by the judge in the absence of an objection from any of the defense attorneys. By failing to object, even at the conclusion of the prosecutor’s argument, defense counsel precluded a measured remedy for the prosecutor’s misstatement. There was no plain error.
E. “Improper depiction of appellants as members of a sinister and vicious drug organization ”
J.D. and to some extent Irick claim that the prosecutor, by use of “inflammatory rhetoric,”31 and otherwise, improperly depicted them as members of an organized drug ring. They contend that this depiction was accomplished by the basic “pitch” of the case, and also, among other thing, by references to Irick as “Dirty Harry” and “the enforcer” and to his weapon as a “cannon.” They also complain that the judge abused his discretion in allowing the prosecutor, during his cross-examination of Irick, to demonstrate the use of the weapon with which Officer Lewis had been shot.
We think that the basic theme of the case was determined by the facts. One appellant, J.D., was selling cocaine from a pouch. His brother was advertising the same wares a short distance away. When J.D. was arrested, Irick came to his rescue with a .44 magnum. The prosecution’s ballistic expert identified the weapon as the largest and most powerful handgun available, explaining that it fires the largest bullet at the highest velocity. Irick shot an officer at J.D.’s behest, and the two men fled together and caused the gun to be hidden. J.D. also attempted to tamper with a witness. If the government’s witnesses were believed as to what happened, then this was not a case of some choir boys engaged in a naughty prank. Rather, the record illustrates the force of Detective Brown’s testimony about the intimate relationship between drugs, guns and, in this case, potentially lethal violence. The prosecutor had no obligation to pull his punches in describing the sordid scene depicted by the evidence. See (William) Powell, supra, 485 A.2d at 599.
That Irick was a “bodyguard” or “enforcer” could reasonably be inferred from the evidence of what he did. The prosecutor occasionally called him both. Expert testimony which the trial judge properly admitted also supported the prosecutor’s characterization of Irick’s role. There was no impropriety.
Cassandra Dorsey testified that she knew Irick as “Dirty Harry.” The trial judge, recognizing the potential for prejudice resulting from the term, instructed both the prosecutor and Ms. Dorsey not to use it. On one subsequent occasion, the prosecutor, apparently inadvertently, made a reference to “Dirty Harry” while examining Ms. Dorsey. Ms, Dorsey also repeated the nickname on approximately three occasions after being directed not to do so, and was properly reproved by the judge. There is no indication of any com*39plicity by the prosecutor in Ms. Dorsey’s failure to adhere to the judge’s directions,32 however, and under these circumstances her lapses are not attributable to the government. Carter v. United States, 497 A.2d 438, 441 (D.C.1985).
References to Irick as “Dirty Harry” also came before the jury on Ms. Dorsey’s redirect examination, but the judge held that the defense had “opened the door.”33 Although we agree with our dissenting colleague that the doctrine of “curative admissibility” can be over-used, and although the judge would have been acting within his discretion if he had excluded the grand jury testimony despite defense counsel’s inquiry on cross-examination, we do not think that he abused that discretion by ruling the other way. The issue of Ms. Dorsey’s credibility was critical, and the implication on cross-examination that her prior testimony about Irick was recently fabricated went directly to that issue. Moreover, even if the admission of the evidence was erroneous, we are confident that any error was harmless, for the nickname added little to the evidence itself.34
During the cross-examination of Irick, the prosecutor pulled the trigger of the latter’s weapon on several occasions to show that it had to be recocked each time before firing. The trial judge explained the purpose of the demonstration as follows:
In the context of this trial where the witness has testified that he — just after the first shot just panicked, and even as to the first shot wasn’t trying to hurt anybody, after the first shot he panicked^35! ... and therefore he took the gun down from their heads, at which it was originally pointed, to shoot Officer Lewis in the hand.
It seems to me that the — the firing mechanism of this particular gun, that is, the effort it takes to pull the hammer back before you can pull the trigger is a relevant piece of evidence.
The trial judge has broad discretion in determining whether, and in what fashion,36 courtroom demonstrations should be permitted, for he is in the best position to *40“judge whether the game is worth the candle,” i.e., to weigh probative value against potential prejudice. Hamilton v. Pepsi Cola Bottling Co., 132 A.2d 500, 502 (D.C.1957), cert. denied, 356 U.S. 961, 78 S.Ct. 1000, 2 L.Ed.2d 1068 (1958); McCormick on Evidence § 215 at 677 (3d ed. 1984 and Supp.1988). We may disturb the judge’s decision that the evidence is more probative than prejudicial only upon a showing of grave abuse of discretion. Morgan v. District of Columbia, 263 U.S.App.D.C. 69, 83-84, 824 F.2d 1049, 1063-64 (1987); see also Dailey v. District of Columbia, 554 A.2d 339, 340-41 (D.C.1989). Appellants have made no such showing here.
VI
We have considered all of appellants’ other contentions and conclude that they are without merit.37 Applying the legal standards set forth at pp. 32-33, supra, we are satisfied that the prosecutor’s lapses described in this opinion, individually or in the aggregate, were not nearly as serious as Irick and J.D. claim, that the trial judge handled the issues responsibly, that the government’s case, if believed, was compelling, and that Irick and the Daniels brothers were not denied a fair trial. Accordingly, the convictions of all three appellants are hereby Affirmed.
. The use of initials for the Daniels brothers appears to us to be the easiest way to differentiate between them as we recount their respective roles in the events which have resulted in this opinion.
. The evidence in this lengthy trial was extensive and at times complex. We outline only so much of it as is necessary to comprehend this opinion.
. Over the prosecutor’s objection, the trial judge granted a defense motion to strike testimony by Detective Brown to the effect that the other members of a distribution unit would know of the presence of the enforcer. At the close of the government case, and consistently with this ruling, the judge granted defense motions for judgment of acquittal of conspiracy charges against the three appellants, reasoning that there was no proof beyond a reasonable doubt of an agreement between them.
. J.D. and Irick attempted to bolster their defense that the two apparent robbers never identified themselves as police officers by their cross-examination of civilian witnesses who never heard such identification and by prior statements by Officer Lewis in which he did not claim that he had so identified himself.
. Irick’s girl friend, Deborah Williams, testified as to his whereabouts prior to the commission of the crime and confirmed that he stated he was going out to buy cocaine. She admitted on the witness stand that she had lied to the grand jury and to the petit jury, and the trial judge remarked that her credibility had been annihilated.
. The trial judge granted L.D.’s motion for judgment of acquittal on all of the other charges against him.
. At a fast walk. We conclude that little or no weight should be given to L.D.’s "flight" under these particular circumstances.
. See 2 WIGMORE ON EVIDENCE § 278(2) at 133 (Chadbourn rev. ed. 1979); Fox v. United States, 421 A.2d 9 (D.C.1980). “False exculpatory statements made to law enforcement officers constitute independent circumstantial evidence of guilty consciousness.” Commonwealth v. Glass, 486 Pa. 334, 346-47, 405 A.2d 1236, 1242 (1979).
. Our dissenting colleague takes us to task for condemning guilt by association in principle but, in his view, countenancing it in practice. We think our deeds conform to our words.
It is undisputed that L.D. offered to sell an officer cocaine, and proof that he did so was altogether independent of the blood relationship between him and J.D. That relationship is relevant only to the question whether the hawking of cocaine by L.D. and its sale by J.D., when the two men were twenty-five feet apart and far from home, were part of the same operation. We do not think that our recognition in that context of the relevance of the two men’s sib-linghood (to the question whether there were two drug operations or only one) impairs anyone’s constitutionally protected associational rights.
.Or, more precisely, that the jury could not find beyond a reasonable doubt that it was no coincidence.
. L.D. has not claimed that he was denied a fair trial as a result of prosecutorial misconduct, and we therefore do not directly address our dissenting colleague’s assertion as to prejudicial spillover. Our affirmance of the convictions of Irick and J.D. makes the issue academic in any event.
. In Hinnant, the expert witness testified, among other things, that a person with a large sum of money, together with a quantity of pure heroin and "one street bag that is ready to go,” is likely to be "selling dope." He further testified that a drug seller in such circumstances would be likely to carry a gun to avoid being robbed. This court sustained the admission of this evidence, rejecting the contention that it usurped the jury’s prerogative or addressed the "ultimate issue.” Id. at 294 n. 2.
. For purposes of determining whether a defendant has preserved his rights, we have held that a motion for a mistrial at the end of the prosecutor’s initial closing argument is timely, for a contrary rule would encourage disruptive interruptions of the prosecutor’s closing. Hawthorne v. United States, 476 A.2d 164, 169-70 (D.C.1984); Powell v. United States, 455 A.2d 405, 408 n. 1 (D.C.1982).
. The Court also quoted from Johnson v. United States, 318 U.S. 189, 202, 63 S.Ct. 549, 555-56, 87 L.Ed. 704 (1943) (Frankfurter, J., concurring), as follows:
In reviewing criminal cases, it is particularly important for appellate courts to relive the whole trial imaginatively and not to extract from episodes in isolation abstract questions of evidence and procedure. To turn a criminal trial into a quest for error no more promotes the ends of justice than to acquiesce in low standards of criminal prosecution.
470 U.S. at 16, 105 S.Ct. at 1047.
.This court was quoting from United States v. Goodman, 110 F.2d 390, 394 (7th Cir.1940).
. We are not concerned here with improprieties of which the judge was not or could not be aware, such as the withholding of exculpatory evidence.
. Ms. Dorsey emphatically denied any impropriety by the prosecutor, but testified that J.D. told her in a telephone conversation after his arrest that she should pretend that she could not remember relevant facts because she had been under the influence of drugs.
. In the judge’s words,
Assuming a good faith basis to believe that the event inquired about occurred, there really is no doctrine of law that I'm aware of except for notions of civility and gentility that would require the defense to first ask the court before inquiring in that area.
.The judge also expressed the view that, given the personal attacks on the prosecutor’s integrity earlier in the trial, any accusatory response by the prosecutor which carried over to defense counsel — and the judge repeated his view that no such carry-over occurred — would be less prejudicial than under other circumstances. The Supreme Court made the same point in United States v. Young, supra, 470 U.S. at 17, 105 S.Ct. at 1047. The Court also stressed, and *34we agree, that two wrongs do not make a right, and that it is appropriate for the judge to control improper defense tactics by corrective instructions or by an admonition to the "errant advocate,” rather than by allowing the adversary to respond in kind. Id. at 12-14, 105 S.Ct. at 1044-45. The problem for the trial judge in this case was that J.D.'s counsel created a fait accompli by posing the accusatory questions, (as the judge eventually recognized that counsel had a legal right to do), without seeking prior leave of court. Even so, we repeat that although conduct by a defense attorney which the judge deems incompatible with notions of civility and gentility may make subsequent improprieties by the prosecutor more understandable, it cannot justify them.
. In context, the prosecutor’s allusion to "manipulators of truth,” although in the plural, appears to have been directed to appellant J.D. who, according to Cassandra Dorsey, had urged her to testify that she could not remember the relevant facts. The prosecutor’s remark that "they slandered the Government back and forth like a ping-pong ball in the last five weeks" however, could be construed as referring to counsel, since the attorneys but not their clients were in action throughout the five-week trial. The reference could also have been to the defense witnesses collectively.
. Moreover, the defense contention was not that the officers were robbing J.D. but that Irick believed that they were. Questioning Officer Lewis about Irick’s perception might not, in our view, have been productive.
.Like many trial judges, Judge Weisberg had a stated policy of discouraging objections during closing argument, so that the flow of counsel's presentation would not be interrupted. He explained, however, that this rule was not an "ironclad” one, and recognized that "there are some things that are so objectionable that [they] simply require interruption so that damage that might be done can be undone.” This practice, as described by the judge, seems to us entirely reasonable. See authorities cited at p. 32, n. 13, supra. Where contemporaneous objections have been discouraged, however, it is the judge’s responsibility to assure that counsel have an opportunity to protect their clients' rights. When counsel appears to be treading close to matters that could cause substantial prejudice, the judge should consider convening a bench conference sua sponte, even during argument, to protect a litigant from prejudice.
In the present case, J.D. claims that his counsel did object to the word "sandbagging,” but there are 22 lines of transcript relating to other matters between the prosecutor’s use of that term and the next defense objection. When that objection was made, the judge overruled it summarily without interrupting the prosecutor to discern the precise nature of the defense objection. At the conclusion of the prosecutor's argument, J.D.'s counsel requested a mistrial on several grounds, but the allusion to "sandbagging" was not among them. Under these circumstances, we do not think that the issue was adequately preserved for appeal, and we find no plain error.
.The prosecutor asked rhetorically during his initial closing argument why Irick did not tell the truth about his employment record. He failed to allude explicitly to the evidence provided by Irick’s employers which contradicted Ir-ick’s testimony. There was no objection, and Irick’s counsel responded in some detail in his closing argument.
Although the prosecutor's description of Irick's testimony on this subject as untrue, without discussing the supporting evidence, was unfortunate, we are confident that the jurors could connect that description with the record testimony on the point and would not believe that the prosecutor’s remark was based on some undisclosed information in his possession. Moreover, the issue was collateral and it is most unlikely that the incident had any impact on the verdict.
. The judge expressly cautioned counsel to stay away from name-calling and, in particular, from calling any witness a liar.
. For a discussion of an advocate’s ethical responsibilities in this regard, see Young, supra, 470 U.S. at 7-8, 105 S.Ct. at 1042-43.
. The Supreme Court analyzed the problem in this way in Young, supra, 470 U.S. at 18-19, 105 S.Ct. at 1047-48.
The prosecutor’s vouching for the credibility of witnesses and expressing his personal opinion concerning the guilt of the accused pose two dangers: such comments can convey the impression that evidence not presented to the jury, but known to the prosecutor, supports the charges against the defendant and can thus jeopardize the defendant’s right to be tried solely on the basis of the evidence presented to the jury; and the prosecutor’s opinion carries with it the imprimatur of the Government and may induce the jury to trust the Government’s judgment rather than its own view of the evidence.
. Defense counsel also vigorously attacked the credibility of the opposition’s witnesses. J.D.’s attorney, who told the jury, as the prosecutor did, that "I'm not saying anybody lied in this courtroom,” nevertheless said of the government’s expert that "he’ll say anything” and that "he’ll tell you what needs to be told.” He also made some ambiguous remarks which could reasonably be construed as accusing the government of "molding” and "shaping” the evidence to make his client seem guilty. Irick's counsel argued that Cassandra Dorsey came down to court "to share fabricated information, we submit.”
.The prosecutor’s comment that he valued his character, of which appellants also complain, was obviously directed to the intimations by J.D.’s attorney that he had pressured Cassandra Dorsey to lie for the government. It cannot reasonably be viewed as a statement vouching for the veracity of his witnesses.
. E.g., Irick testified that he came a substantial distance to buy cocaine from J.D. although he did not know him well and had bought drugs from him only once, at a different location. He related that, evidently by coincidence, he was transporting his "antique” weapon from one parent's garage to the other parent’s home when an extraordinary occasion for using it — an apparent armed robbery of J.D. by robbers who turned out to be police officers — unexpectedly arose. He then fled to the home of a man he hardly knew, and left his "antique” gun with the man’s brother. Irick's version also required the jury to believe that the officers failed to identify themselves when Irick was about to shoot Officer Lewis, or even thereafter. Reasonable jurors might find it improbable that the officers would thus augment the risk of death to avoid disclosure.
. We entertain some doubt that the prosecutor intended his recitation to be understood as describing J.D.’s precise words. The occasion was hardly one in which J.D. would have focused on the precise violation for which he was in danger of being imprisoned.
. In rhetoric that itself is not exactly understated, J.D. claims that "the prejudicial impact of the prosecutor’s misconduct cannot be overstated.” Indeed, J.D.’s brief is replete with adjectives such as egregious, outrageous, “rife with classic improprieties,” etc. where, at least to the writer, nouns and verbs would have been at least as persuasive.
. The trial judge, who was in a position to evaluate the situation first hand, remarked that "the reason it happened is because that [Dirty Harry] is the only way she knows him by.”
. On cross-examination, Ms. Dorsey had been interrogated about whether she knew Irick under a different nickname. To counteract the implications of this line of questioning, the prosecutor read Ms. Dorsey’s grand jury testimony to the jury. The trial judge ruled that
the reference to Dirty Harry, all that was a quotation from the questions and answers in the witness’ grand jury testimony. And it seems to me that it was not only fairly opened up by [Irick’s counsel], ... it was almost necessarily opened up, and that the redirect examination was entirely proper.
None of the defense attorneys objected to the allusions to Dirty Harry while the testimony was being read or requested redaction. Instead, they moved for the more drastic remedy of a mistrial after the allegedly offending words had been read.
. Following the popularity of the Clint Eastwood motion picture so titled, the term “Dirty Harry” has come to connote a tough man with a .44 magnum. There was far more than this unwanted sobriquet to show that Irick was such a man. He admitted that he had the weapon in question and that he had previously kept it at his father’s garage. He claimed to have been transporting it to his mother’s house. He acknowledged having taken it with him on an expedition to purchase unlawful drugs — rather an odd destination for an antique — and that he had used it to shoot a man who turned out to be Officer Lewis. On these facts, it was surely the evidence of Irick’s connection with and use of the .44 magnum, rather than the proscribed allusions to his alleged nickname, that resulted in his conviction. Any claim of prejudice to J.D. in this connection is even more tenuous, for the nickname was personal to Irick and conveyed little if anything about his codefendants.
. Irick had testified that "it happened so fast I couldn't think no way" before pulling the trigger.
. If, as the dissent suggests, the demonstration had been effected by an expert witness, this might have occurred days after Irick had given the version of events which the prosecutor was attempting to refute by showing how the weapon worked. Moreover, it would have been impossible to confront Irick contemporaneously with the apparent contradiction between his testimony and the actual operation of the .44 magnum. See also United States v. Skinner, 138 U.S.App.D.C. 121, 124, 425 F.2d 552, 555 (1970) (proper exercise of discretion to allow prosecutor to stand on courtroom table to simulate defendant's position in ledge above victim of an assault).
. We specifically hold that the prosecutor committed no impropriety by his “folksy” recitation of an "old Arizona saying” that if the defense case is weak, "you slander the prosecutor." This case is unlike Curry v. United States, 520 A.2d 255, 267 (D.C.1987), in which this court viewed as improper the prosecutor's characterization of a defense on the merits — that the police “planted” the drugs — as a last resort of a defendant “who had nothing left.”
We also reject as baseless J.D.'s contention that the prosecutor engaged in misconduct by arguing that, if Irick’s testimony was truthful, the prosecution witnesses must have lied. The salutary rule that a cross-examiner may not ask a witness whether other witnesses are lying, (Wayne) Carter v. United States, 475 A.2d 1118, 1126 (D.C. 1984), cert. denied, 469 U.S. 1226, 105 S.Ct. 1222, 84 L.Ed.2d 362 (1985), because, as the trial judge ruled in this case, one witness may not express an opinion about another's credibility, does not preclude an attorney from drawing reasonable inferences during his closing argument from contradictory testimony in the record.