concurring:
I concur with my colleagues as to the disposition of this case. I write separately, however, to add my thoughts on some of the issues raised in Section III.A. of the majority opinion concerning the exclusion of certain evidence at trial.
I.
Hill contends that evidence critical to his defense was excluded and that this exclu*308sion unconstitutionally prevented him from mounting a full defense. In particular, he claims that testimony from Suman Shres-tha, a witness with whom Emmanuel purportedly had a relationship, as well as a gift letter executed by Emmanuel on behalf of Shrestha, should have been admitted. First, Hill argues that the evidence was admissible to show Emmanuel’s bias. Second, he argues the evidence was proper under Rule 404(b) because it tended to show Emmanuel’s motive, intent, and plan to fabricate testimony concerning his dealings with Hill, as well as a lack of any motive or intent on Hill’s part. Third, Hill argues that he should have been allowed to cross-examine Emmanuel about the Shres-tha incident under Rule 608(b) because it was relevant to the issue of Emmanuel’s truthfulness. Taken together, Hill contends that, because the court permitted no exploration of the Shrestha incident, he was deprived of the right to confront his accuser, in violation of the Sixth Amendment. For its part, the government argues that the Shrestha evidence was “reverse 404(b)” evidence that was properly excluded as mere “propensity evidence.” J.A. 160-61. The government also argues that, even if the evidence was relevant (a point the government does not concede), the introduction of the evidence would have led to a trial within a trial, considerable confusion as to the issues before the jury, and harassment of the witness, and that the evidence was therefore excludable under Rule 403.
Each of these claims raises important issues. We review the district court’s decision as to admissibility for abuse of discretion, which we will not find unless the decision was “arbitrary and irrational.” United States v. Weaver, 282 F.3d 302, 313 (4th Cir.), cert. denied, — U.S. -, 123 S.Ct. 186, 154 L.Ed.2d 75 (2002). Having reviewed the trial transcript, I ultimately agree that the court did not abuse its discretion in excluding the evidence and did not violate Hill’s Sixth Amendment rights.
II.
Hill first argues that the court should have admitted the Shrestha evidence because it demonstrated Emmanuel’s bias toward Hill. Hill’s defense was that he and Emmanuel had a long-term personal relationship and that Emmanuel voluntarily gave Hill control over his assets because of that relationship, and that Emmanuel changed his mind when the relationship ended poorly. This defense was not without some evidentiary support — the documentary evidence introduced by the government showed that the initial transactions giving rise to the charges against Hill bore Emmanuel’s signature, authorizing Hill to act on Emmanuel’s behalf. According to Hill, the Shrestha evidence supported his bias claim by showing that Emmanuel in the past had made a monetary gift to a friend, documented that gift, and then tried to recharacterize the gift as a loan once the relationship dissolved, as a way of punishing the friend for abandoning him. This kind of evidence, however, does not comport with a strict definition of bias. As the Supreme Court has noted, “[b]ias is a term used in the ‘common law of evidence’ to describe the relationship between a party and a witness which might lead the witness to slant, unconsciously or otherwise, his testimony in favor of or against a party.” United States v. Abel, 469 U.S. 45, 52, 105 S.Ct. 465, 83 L.Ed.2d 450 (1984). Although there might exist other evidence of a relationship between Hill (as a party) and Emmanuel (as witness), the evidence proffered by Hill had to do with Emmanuel’s relationship with Shrestha, a third party who was not involved in the proceedings *309or in any of the events surrounding the dispute between Hill and Emmanuel. Therefore, Shrestha’s testimony and the documentary evidence surrounding his dealings with Emmanuel is not properly characterized as evidence of Emmanuel’s bias toward Hill. See, e.g., United States v. McNatt, 931 F.2d 251, 256 (4th Cir.1991) (holding that a document in which a police officer purported to admit fabricating evidence in another case was not admissible to show bias against the defendant where the document made no mention of the defendant and contained nothing to show evidence of a relationship between the officer and the defendant); United States v. Greenwood, 796 F.2d 49, 54-55 (4th Cir.1986) (concluding that the district court did not improperly preclude cross-examination of a prosecution witness where the subject of the witness’ testimony was not probative of the witness’ animosity toward the defendant or favoritism toward the government and therefore not probative of bias).
The Shrestha evidence is more aptly considered under Rule 404(b), as evidence of Emmanuel’s motive, intent, or plan, and the test for its admissibility therefore comes from United States v. Queen, 132 F.3d 991 (4th Cir.1997). As a general proposition, evidence that tends to make the existence of a fact of consequence to an issue in the case more probable or less probable than without the evidence is admissible, id. at 994; see also Fed.R.Evid. 401 and 402. Rule 404(b) recognizes the potentially probative value of evidence about prior “crimes, wrongs, or acts.” Fed.R.Evid. 404(b). Although “not admissible to prove the character of a person in order to show action in conformity therewith,” such evidence may be admissible when offered to show motive, opportunity, intent, and other similar purposes. Id. However, relevant evidence proffered under 404(b) can be excluded if its probative value is “substantially outweighed” by the potential for unfair prejudice, confusion of the issues, undue delay, or redundancy. Fed.R.Evid. 403.
In light of these general principles, we have determined that evidence is admissible under Rules 403 and 404(b) in the following circumstances:
(1) The evidence must be relevant to an issue, such as an element of the offense, and must not be offered to establish the general character of the defendant. In this regard, the more similar the prior act is ... to the act being proved, the more relevant it becomes. (2) The act must be necessary in the sense that it is probative of an essential claim or an element of the offense. (3) The evidence must be reliable. And (4) the evidence’s probative value must not be substantially outweighed by confusion or unfair prejudice in the sense that it tends to subordinate reason to emotion in the factfinding process.
Queen, 132 F.3d at 997.
In its discretion, the district court here could have decided that the allegations and the circumstances surrounding the Shres-tha incident and the instant case were too dissimilar and too contentious to warrant admission of the evidence. There were numerous differences between the incidents that would have likely led to confusion and a possible “trial within a trial.” For example, the proffered Shrestha evidence concerned a civil suit filed by Emmanuel arising from a one-time gift that Emmanuel allegedly sought to recharac-terize as a loan. By contrast, Hill represented himself to Emmanuel as a professional financial advisor and principal in two investment companies (which turned out to be bogus), and he thereafter engaged in a series of transactions involving Emmanuel’s investment portfolio. Unlike the *310Shrestha situation, it was the government, not Emmanuel, that pressed charges against Hill after a third party’s review of Emmanuel’s financial records revealed that Hill had emptied Emmanuel’s accounts.
Besides these differences, as Judge Gregory points out, the government never conceded the reliability of any of the Shrestha evidence. Without a doubt, the court would have faced a contentious trial within a trial and the very real possibility of jury confusion by permitting litigation of the alleged Shrestha affair. For these reasons, I cannot conclude that the district court erred in deciding that the Shrestha incident and the present case were too dissimilar, that questions of reliability surrounded the proffer, or that considerable risk of confusion would have attended admission of the disputed evidence under Rule 404(b).
These same considerations answer Hill’s argument that he should have been allowed to cross-examine Emmanuel concerning the Shrestha incident under Rule 608(b). This rule permits crossexamination of a witness as to specific instances of conduct in order to test his character for truthfulness. Presuming, without deciding, that the nature of the Shrestha evidence is indicative of untruthfulness, the language of the rule nevertheless places the decision whether to admit such evidence in the discretion of the trial judge:
They [specific instances of the witness’ conduct] may, however, in the discretion of the court, if probative of truthfulness or untruthfulness, be inquired into on crossexamination of the witness ... concerning the witness’ character for truthfulness or untruthfulness.
Fed.R.Evid. 608(b) (emphasis added). The considerations outlined in Rule 404(b) still apply in the context of Rule 608(b). As this court has stated, “[t]he purpose of [Rule 608(b) ] is to prohibit things from getting too far afield — to prevent the proverbial trial within a trial.” United States v. Bynum, 3 F.3d 769, 772 (4th Cir.1993). Once again, the district court did not abuse its discretion in deciding not to permit this evidence before the jury.
The exclusion of any inquiry into the Shrestha evidence under 608(b) underscores that there are constitutional implications to the district court’s ruling. Because Hill’s defense was that the transfers from Emmanuel’s accounts were authorized and that Emmanuel lied about the transactions when the relationship soured, Hill argues that, in being prevented from any exploration of the Shrestha incident, he was prevented from offering highly relevant evidence in violation of his constitutional right to present a defense. See, e.g., Chambers v. Mississippi, 410 U.S. 284, 294, 93 S.Ct. 1038, 35 L.Ed.2d 297 (1973) (“The right of an accused in a criminal trial to due process is, in essence, the right to a fair opportunity to defend against the State’s accusations.”). In addition, Hill argues that the failure to allow him to cross-examine Emmanuel about the Shrestha issue violated his rights under the Confrontation Clause. See, e.g., Olden v. Kentucky, 488 U.S. 227, 231, 109 S.Ct. 480, 102 L.Ed.2d 513 (1988) (explaining that a defendant’s Sixth Amendment right to confront witnesses against him “includes the right to conduct reasonable cross-examination”); Delaware v. Van Arsdall, 475 U.S. 673, 680, 106 S.Ct. 1431, 89 L.Ed.2d 674 (1986) (“[A] criminal defendant states a violation of the Confrontation Clause by showing that he was prohibited from engaging in otherwise appropriate cross-examination designed to show a prototypical form of bias on the part of the witness, and thereby to expose to the jury the facts from which jurors could appropriately draw inferences relating to the reliability of the witness.” (internal quotation marks and alteration omitted)).
*311The references to “reasonable” or “appropriate” areas of cross-examination in Olden and Van Arsdall remind us that the Confrontation Clause does not “prevent[ ] a trial court from imposing any limits on the scope of defense counsel’s cross-examination and presentation of evidence related to the impeachment of a key prosecution witness’s credibility.” Quinn v. Haynes, 234 F.3d 837, 847 (4th Cir.), cert. denied, 532 U.S. 1024, 121 S.Ct. 1968, 149 L.Ed.2d 762 (2001). Rather, courts retain “wide latitude ... to impose reasonable limits on such cross-examination based on concerns” such as confusion of the issues, lack of relevance, or potential harassment. Id. (internal quotation marks omitted). The question here is whether the court, in preventing Hill from any exploration of the Shrestha evidence, exceeded the scope of latitude enjoyed by trial courts in making such determinations. Once again, I find no error in the district court’s decision that the Shrestha evidence was too far afield of the issues under consideration to shed any light on Emmanuel’s alleged bias or motive and that considerable confusion and potential harassment would have attended its admission. At the same time, Hill was permitted to directly challenge Emmanuel’s testimony on cross-examination, including Emmanuel’s obviously shaky memory as to the circumstances under which he granted authority to Hill to conduct his affairs, as well as numerous other aspects of his testimony. The court’s refusal to allow Hill to explore allegations surrounding Emmanuel’s dealings with Shrestha did not prevent Hill from reasonable and appropriate cross examination of Emmanuel concerning his dealings with Hill. Under these circumstances, I too believe Hill has not made a showing that his constitutional rights were violated.