Paul and Leroy Miller, the appellants in this consolidated appeal, were convicted of conspiracy and several substantive offenses arising from a check-forging scheme. On appeal, Paul Miller challenges trial court rulings allowing the Government to elicit testimony from two witnesses concerning his prior criminal conviction. Leroy Miller contests the sufficiency of the evidence underlying his conviction for conspiracy.

We affirm both convictions. We reject Paul Miller's claim that evidence of a defendant's past crimes can never be introduced to show a witness ' state of mind, and find that the District Court properly admitted the disputed testimony of one witness for this purpose. Although the trial court should have excluded the testimony of the second witness, the admission of this evidence was harmless error. The evidence against Leroy Miller amply supports the jury's verdict.

Paul and Leroy Miller were charged in a four-count indictment with conspiracy to commit bank fraud ("Count One"), see 18 U.S.C. Sec. 371 (1988), and bank fraud, see 18 U.S.C. Sec. 1344 (1988).1 Evidence at trial established that Paul Miller's girlfriend, Myrna Mann, used her position as a secretary at a Washington bank to procure forged checks totalling some $37,000. The Government's theory of the case was that Paul Miller coerced Mann into furnishing the checks, and that both Millers recruited payees to cash the checks in return for a fee. See Trial Tr. I at 21-22 (Government's opening statement). The theory of the defense was that Mann, who by the time of the trial had pleaded guilty to embezzlement, devised the check-forging scheme on her own and implicated Paul and Leroy Miller as part of a plea bargain. See Trial Tr. I at 26 (Paul Miller's opening statement);2 id. at 28 (Leroy Miller's opening statement). Leroy Miller maintained, in addition, that he was too marginal a participant in the scheme to be convicted for conspiracy. See id. at 28 (opening statement).

At two points in the trial, disputes arose over whether the Government would be permitted to introduce evidence of Paul Miller's previous conviction for robbery. The first was when the Government, on the first day of trial, informed the court that it intended to elicit testimony concerning the conviction from Mann. Paul Miller's counsel objected to the proposed testimony as irrelevant and prejudicial; the Government argued that evidence of Mann's awareness of Paul Miller's criminal record was necessary to lend credibility to her claim that she had been coerced into participating in the check-forging scheme. See Trial Tr. I at 7-8, 10. The judge ruled that the evidence could be admitted, stating:

Well, I will try to cut the baby in half to the extent that I can. I am going to allow her to testify that she was being threatened, and that she knew that Paul Miller had a prior criminal record and had served time, without going into the specific offense.

If the jury doesn't believe on the basis of that that she was threatened, then so be it. But some balance has to be struck here between the defendants' rights and the Government's need to bring that woman in and have her testify.

Now, of course, if on cross-examination doubt is cast on her story as to why was she really afraid or whatever, it may be that you can recall her on redirect or whatever. You may be able then to bring out more. That depends entirely on what happens on cross-examination. But at least on direct all she can say ... [is] that she was threatened, and she felt there was validity to the threat in view of the fact she knew he had a prior criminal record and he had served time.

Trial Tr. I at 10-11. Mann was permitted to testify on this basis.3

The issue of Paul Miller's conviction came up again during the testimony of Tracie Barnes. Barnes was a payee on one of the forged checks, and she testified that she agreed to cash the check for Paul Miller in exchange for $2,000--one-fourth of the check's value. See Trial Tr. II at 9-10. After completing direct examination, the Government requested permission to reopen so that it could elicit testimony from Barnes that she had agreed to cash the check because she knew that Paul Miller had recently been released from prison and surmised that he did not have a checking account. See id. at 11-13.4 Paul Miller's counsel again objected. See id. at 12. The judge responded:

We've got to know. All this is ridiculous. We have to have some explanation of what went on, why she cashed a check for some total stranger. The jury is entitled to know that.

....

It's already been brought out he was in jail.

....

It's not prejudicial at all if it was already brought out. It seems to me the jury is entitled to know why a total stranger would go and handle a cashier's check.

Id. at 12, 13. During a five-minute recess, the prosecutor explained to Barnes that she could testify only that Paul Miller had a criminal record but could say nothing about the nature of the offense for which he had been convicted; the Government was then permitted to elicit the disputed testimony.5

The jury ultimately returned guilty verdicts against both appellants on all counts, and this appeal ensued.6 Paul Miller continues to challenge the admission of the evidence pertaining to his prior conviction. Leroy Miller argues that the evidence at trial was insufficient to sustain a conviction for the conspiracy charged in Count One.II. ANALYSIS

Paul Miller asserts that the District Court erred both in admitting the evidence of his prior conviction and in failing to issue a limiting instruction, and that each error furnishes an independent ground for reversal. Although we do not find the trial court's treatment of the disputed evidence to be wholly free of legal defect, we conclude that the disputed rulings do not warrant a reversal of Paul Miller's conviction.

a. General Test

The test for analyzing the admissibility of evidence of prior criminal convictions and other "bad acts" is well established. See Huddleston v. United States, 485 U.S. 681, 108 S. Ct. 1496, 1499-1500, 99 L. Ed. 2d 771 (1988). "The threshold inquiry," imposed by Federal Rule of Evidence 404(b),7 "is whether th[e] evidence is probative of a material issue other than character." 108 S. Ct. at 1499. "If offered for such a proper purpose, the evidence is [then] subject only to general strictures limiting admissibility," the most important of which being the requirement of Rule 403 that the probative value of the evidence not be "substantially outweighed" by its potential prejudice.8 Id. at 1500. This two-step analysis--certification of a "proper" and relevant purpose under Rule 404(b), followed by the weighing of probity and prejudice under Rule 403--is firmly rooted in the law of this circuit. See, e.g., United States v. Manner, 887 F.2d 317, 321 (D.C.Cir.1989), cert. denied --- U.S. ----, 110 S. Ct. 879, 107 L. Ed. 2d 962 (1990); United States v. Lavelle, 751 F.2d 1266, 1275 (D.C.Cir.), cert. denied, 474 U.S. 817, 106 S. Ct. 62, 88 L. Ed. 2d 51 (1985).

b. Mann's Testimony

Mann's testimony satisfies the Rule 404(b) step of the analysis. Evidence of Mann's awareness of Paul Miller's criminal record was admitted not "to show action in conformity" with a criminal disposition, FED.R.EVID. 404(b), but rather to lend credence to Mann's claim that she feared for her safety if she did not comply with Paul Miller's demands for bogus checks. See Trial Tr. I at 10. Mann's state of mind was relevant to her credibility, a material issue in the case by virtue of Paul Miller's own trial strategy. See note 2 supra.9

Paul Miller resists this conclusion. Although he acknowledges that the "proper" material issues identified in Rule 404(b)--"motive, opportunity, intent, preparation, plan, knowledge, identity, or absence of mistake or accident"--are not "exhaustive, but merely illustrative," United States v. Moore, 732 F.2d 983, 987 n. 31 (D.C.Cir.1984), he nonetheless infers from this list that admission of bad-acts evidence is permissible under Rule 404(b) only if the evidence relates directly to the conduct of the defendant. See Brief for Appellant Paul A. Miller at 16-17. Citing two Fifth Circuit cases, see United States v. Hernandez, 750 F.2d 1256, 1258 (5th Cir.1985); United States v. Wesevich, 666 F.2d 984, 988 (5th Cir.1982), he concludes that "[d]emonstrating the state of mind of a witness ... is not a purpose for which evidence of a prior conviction may be admitted pursuant to Rule 404(b)." Brief for Appellant Paul A. Miller at 15.

This argument misconceives the nature of Rule 404(b). The rule was intended not to define the set of permissible purposes for which bad-acts evidence may be admitted but rather to define the one impermissible purpose for such evidence. "Only one series of evidential hypotheses is forbidden in criminal cases by Rule 404: a man who commits a crime probably has a defect of character; a man with such a defect of character is more likely than men generally to have committed the act in question." 2 J. WEINSTEIN & M. BERGER, supra note 9, p 404 at 404-52. In other words, under Rule 404(b), any purpose for which bad-acts evidence is introduced is a proper purpose so long as the evidence is not offered solely to prove character. The Government's right to introduce bad-acts evidence for purposes other than showing a defendant's criminal propensity is by no means unlimited. But the limits derive from the "general strictures limiting admissibility such as Rules 402 and 403," not from Rule 404(b). Huddleston, 108 S. Ct. at 1500.10

Paul Miller's argument that evidence of past bad acts can be submitted only to prove issues relating to the defendant's conduct is inconsistent with case law in this and other circuits. In United States v. Lewis, 701 F.2d 972 (D.C.Cir.1983), the District Court permitted the Government to elicit testimony that the defendant, on trial for gun possession, had been arrested on the basis of an outstanding warrant for assault. We affirmed, ruling expressly that the purpose for which the evidence had been introduced--to defend "the propriety of the behavior of the police" in response to the defendant's claim that he was the victim of manufactured charges--constituted a proper purpose for introduction of the evidence under Rule 404(b). Id. at 975. The Third and Eleventh Circuits, too, have held that Rule 404(b) permits the introduction of bad-acts evidence to prove material issues unrelated to the defendant's conduct, including "the witness' motives." United States v. Scarfo, 850 F.2d 1015, 1021 (3d Cir.), cert. denied, --- U.S. ----, 109 S. Ct. 263, 102 L. Ed. 2d 251 (1988); see United States v. Foster, 889 F.2d 1049, 1053 (11th Cir.1989) (evidence of prior drug transaction "was necessary in order for the jury to understand why [witness] agreed to hide" defendant's illegal drugs). We believe that these cases are more in keeping with the structure of the Federal Rules generally and with Rule 404(b) in particular than are the Fifth Circuit cases cited by Paul Miller.

The admission of Mann's testimony also satisfies the second, Rule 403, step of the Huddleston test. We review for abuse of discretion a trial court's ruling on whether the probity of prior-conviction evidence outweighs its potential for unfair prejudice, and "we lean towards admitting evidence in close cases." Manner, 887 F.2d at 322. The probity of the disputed portion of Mann's testimony is fairly strong; although it is true that Mann could have testified that she felt intimidated by Paul Miller without disclosing his criminal record, Paul Miller's theory of the case--that Mann had "profited" from the scheme and then "cut a deal with the United States Attorney's office to attempt to save herself," Trial Tr. I at 26--put Mann's credibility in issue, creating a need to bring Mann's awareness of Paul Miller's conviction to the jury's attention. Cf. Lavelle, 751 F.2d at 1277 (noting that "prosecution's need for the evidence" is important factor). The prejudicial impact of this evidence is debatable; knowledge of the bare fact that Paul Miller had previously been in jail may have induced a certain amount of speculation as to the nature of his conviction, but in context probably would not have caused the jury to infer that he had a propensity to engage in criminal behavior. In light of these considerations--all of which "are readily apparent from the record," Manner, 887 F.2d at 323--the trial court's determination that the risk of "unfair prejudice" did not "substantially outweigh[ ]" the probative value of the disputed testimony, FED.R.EVID. 403, cannot be said to constitute the " 'grave abuse' " of discretion necessary for reversal. Manner, 887 F.2d at 322 (quoting United States v. Payne, 805 F.2d 1062, 1066 (D.C.Cir.1986)).

Finally, Paul Miller claims that a subsequent allusion to his criminal record in the Government's closing argument magnified the prejudice of Mann's testimony, tipping the balance in favor of reversal. The offending statement was the Government's observation that "[c]ounsel could have explored more on the cross-examination about why [Mann] felt that threat. You didn't hear that, did you?" Trial Tr. II at 97. This comment, Paul Miller argues, unfairly exploited the restraint that he was obliged to exercise in his cross-examination in order to avoid opening the door to further testimony by Mann concerning the details of his robbery conviction.

We are unpersuaded. Even accepting Paul Miller's characterization of the statement, it is not clear to us that the advantage derived by the Government was illicit; by giving Paul Miller the power to exclude the details of his conviction through voluntarily limiting the scope of his cross-examination, the trial court did not also give Miller the right to shield from the jury's attention his failure effectively to impeach Mann. In any event, the Government's statement responded expressly to Paul Miller's closing argument, which repeatedly voiced doubt concerning Mann's testimony. See id. at 84-85, 88. By pressing the issue in his closing, Paul Miller invited the Government's implicit reference to his conviction, see Darden v. Wainright, 477 U.S. 168, 182, 106 S. Ct. 2464, 2472, 91 L. Ed. 2d 144 (1986); United States v. Burnett, 890 F.2d 1233, 1241 (D.C.Cir.1989), a reminder consistent with the purpose for which the trial court properly admitted the evidence in the first instance, see United States v. Boon San Chong, 829 F.2d 1572, 1576 (11th Cir.1987). Viewed in context, the Government's comments, even if objectionable, did not unfairly prejudice Paul Miller.11

c. Barnes' Testimony

Admission of the disputed portion of Barnes' testimony is less defensible. We have serious doubts about the admissibility of this evidence under Rule 404(b). The Government purportedly sought to elicit testimony that Barnes knew of Paul Miller's recent release from jail in order to prove a matter other than Miller's criminal propensity, namely Barnes' innocent moti vation in agreeing to cash a check for him. Insofar as Barnes already had admitted on direct examination that she received $2,000 from Paul Miller for cashing the check, this professed purpose is surely open to question. But even if we take this suggestion at face value, we are at a loss to connect Barnes' awareness of Paul Miller's record with any material issue in the case. Absent any advance indication that Paul Miller planned to put Barnes' state of mind in issue, there was no reason to allow Barnes' testimony. At a minimum, the trial court should have postponed its ruling on admissibility until after Paul Miller had conducted his cross-examination, in order to determine whether the proposed testimony would be relevant to any disputed question. Cf. United States v. Rosse, 418 F.2d 38, 41-42 (2d Cir.1969) (Government may not introduce bad-acts evidence relevant to matter not yet put in issue by defense), cert. denied, 397 U.S. 998, 90 S. Ct. 1143, 25 L. Ed. 2d 408 (1970).

The Rule 403 inquiry is even less satisfying.12 The probative value of Barnes' testimony was infinitesimal. Barnes' admission that she had received $2,000 seemed to make it perfectly clear why she agreed to cash the bogus check; indeed, her claim that she cashed the check on good-Samaritan grounds would appear to be patently pretextual. Furthermore, even if true, Barnes' testimony was irrelevant to any material issue in the case. The trial court reasoned that Barnes' testimony would not be unfairly prejudicial since evidence of Paul Miller's conviction was already before the jury. But because Barnes' testimony on her motivation had so little probity, we believe that the trial court abused its discretion in admitting this testimony.

Nonetheless, after carefully reviewing the record, we are constrained to find that the erroneous admission of Barnes' testimony was harmless. See FED.R.CRIM.P. 52(a). We will not upset a criminal conviction because of an erroneous evidentiary ruling "[i]f (1) the case is not close, (2) the issue not central, or (3) effective steps were taken to mitigate the effects of the error." United States v. Hernandez, 780 F.2d 113, 119 (D.C.Cir.1986). Both the first and second of these criteria are easily met. The strength of the Government's case against Paul Miller was overwhelming. In addition to Mann and Barnes, two other witnesses recounted in terms similar to the testimony furnished by Barnes their agreement to cash bogus checks supplied by Paul Miller, see Trial Tr. I at 110-13; Trial Tr. II 25-37; Miller put on no defense. Nor was the issue of whether Barnes acted innocently central to either her testimony or the case against Paul Miller generally. Consequently, admission of the disputed portion of Barnes' testimony does not warrant reversal.13

Notwithstanding the absence of any request by trial counsel, Paul Miller argues that the District Court's failure to issue a limiting instruction constitutes an independent ground for reversal. In support of this contention, he relies on United States v. Lewis, 693 F.2d 189, 197 (D.C.Cir.1982), in which we held that the District Court must issue such an instruction sua sponte when "the evidence has the potential for substantially prejudicing the defendant." He also relies on the plain error doctrine. See FED.R.CRIM.P. 52(b).

Paul Miller's reliance on Lewis is without merit. Under the circumstances, we do not believe that admitting the disputed testimony without a limiting instruction "substantially prejudiced" Miller; viewed in context, the brief and noninflammatory references to Miller's criminal record were likely to be considered only in regard to the purpose for which they were admitted--to explain the motives of the witnesses for participating in the check-forging scheme.14 Paul Miller's suggestion that prior-conviction evidence invariably causes "substantial prejudice" is inconsistent with Lewis' express rejection of "the broad prophylactic rule that a trial court must give an immediate though unrequested cautionary instruction" whenever it admits evidence pursuant to Rule 404(b); "the burden ... to guard against any potential misuse of evidence," we made clear, should be borne by defense counsel, not by the trial court. 693 F.2d at 196.15

We are also faced here with a situation where "astute defense counsel may [have] prefer[red] tactically to forego [an instruction] in the interest of avoiding its inevitable focus of the jury's attention on the unfavorable evidence." United States v. Childs, 598 F.2d 169, 176 (D.C.Cir.1979). The inference that Paul Miller's counsel deliberately declined to request an instruction is strongly supported by the record, which indicates that when the trial court was considering whether to admit Mann's testimony, counsel for Leroy Miller did request that the court instruct the jury to consider the prior-conviction evidence only against Paul Miller, not against Leroy Miller. See Trial Tr. I at 9; see also id. at 11 (court indicating that it would instruct jury "that this is admissible only in regard to the relations between her and Paul Miller"). It cannot credibly be maintained, then, that Paul Miller's counsel simply overlooked this option.

Finally, we reject Paul Miller's contention that the trial court's failure to issue an unrequested limiting instruction constituted "plain error." Because, under these circumstances, the trial court had no obligation to issue an instruction sua sponte, there was no error, plain or otherwise. Cf. United States v. Blackwell, 694 F.2d 1325, 1342 (D.C.Cir.1982) (error must be absolutely clear under settled law in order to fall within "plain error" doctrine).

Leroy Miller maintains that the evidence at trial does not support his conviction for the conspiracy charged in Count One.16 He bases this contention on two independent grounds. First, he claims that the evidence does not satisfy the elements of conspiracy to commit bank fraud. See Brief for Appellant Leroy Miller at 4-8. Second, he maintains that the evidence at trial failed to prove the conspiracy as charged in Count One. No evidence was introduced, Leroy Miller argues, linking him to the conspiracy at its alleged origin or showing that he communicated directly with Mann; the evidence at best proved two or more smaller conspiracies: one between Mann and Paul Miller, and one or more between Paul Miller and Leroy Miller. This variance between the indictment and the proof at trial, Leroy Miller contends, mandates reversal. See id. at 8-14.

Both components of Leroy Miller's argument are unpersuasive. Evidence at trial demonstrated that Mann furnished bogus checks to Paul Miller, see Trial Tr. I at 43, that on at least one occasion Leroy Miller recruited a payee for one of the checks, see Trial Tr. II at 34-37, and that Leroy Miller himself was a payee for another of the checks, see Trial Tr. I at 64. From this evidence, a rational factfinder could easily infer that Leroy Miller agreed with Paul Miller and Count One's unindicted coconspirators intentionally and knowingly to commit bank fraud, and that either Leroy Miller or Paul Miller or both had engaged in an overt act in furtherance of that agreement. See 18 U.S.C. Sec. 371.

The variance claim is equally devoid of merit. Whether the evidence presented at trial proves a single conspiracy is a matter of fact for the jury. See United States v. Tarantino, 846 F.2d 1384, 1391-92 (D.C.Cir.), cert. denied, --- U.S. ----, 109 S. Ct. 108, 102 L. Ed. 2d 83 (1988). Given the coconspirators' common goal to defraud Mann's employer, and the general interdependence of their efforts to achieve that end, the jury's finding of a single conspiracy in this case is amply supported by the evidence. See id. at 1392-93. See generally Blumenthal v. United States, 332 U.S. 539, 557-58, 68 S. Ct. 248, 256-57, 92 L. Ed. 154 (1947). So long as their mutual efforts contributed to the success of a common criminal design, it need not be shown that Leroy Miller knew or communicated with Mann or any other unnamed coconspirator. See id. at 558, 68 S.Ct. at 257. Nor need it be shown that Leroy Miller was complicit in the check-forging scheme from its inception in order to tie him to the charged conspiracy. See, e.g., United States v. Bridgeman, 523 F.2d 1099, 1107-08 (D.C.Cir.1975), cert. denied, 425 U.S. 961, 96 S. Ct. 1744, 48 L. Ed. 2d 206 (1976).17 In sum, we find no error in the jury's verdict.

None of the issues raised by the appellants warrants reversal. Testimony from one witness concerning her awareness of Paul Miller's criminal record was properly admitted to show the witness' motive for participating in the alleged check-forging scheme, while admission of similar testimony from a second witness was harmless error. The evidence amply supports Leroy Miller's conviction for conspiracy. We therefore affirm both convictions.

Affirmed.