On July 30, 1990, the Providence Police executed a state-court search warrant at the residence of appellant Ralph Carty and seized several firearms and a small quantity of cocaine. Carty was tried and convicted on two firearms charges but acquitted on a cocaine charge. Carty contends on appeal that (1) the evidence seized at the residence should have been suppressed because the warrant affidavit contained false statements; (2) at the suppression hearing the district court improperly restricted cross-examination of the affiant; and (3) the court improperly admitted "other act" evidence at trial. We affirm.

* DISCUSSION

The warrant affidavit, provided by Detective Nicholas Cardarelli of the Providence Police Department, formed the primary focus of the Franks hearing1 conducted before the district court.2

Although the Cardarelli affidavit, dated July 30, 1990, indicated that the controlled buy had taken place within the preceding "few days," Cardarelli subsequently learned that Carty and his family were on vacation during that time and had not returned to their residence until the evening of July 29. At the suppression hearing, Cardarelli testified that the controlled buy took place between 2:00 and 4:00 p.m. on July 30. He explained that it was normal police procedure not to reveal the exact date of the controlled buy so as to protect the identity of the confidential informant. Cardarelli testified that he drove the informant to the tenement in which Carty occupied a first-floor apartment, observed the informant enter and emerge shortly thereafter with a small baggie containing a substance that appeared to be cocaine, returned to the Special Investigation Bureau ("SIB") office, and performed a field test on the substance. As the test indicated the presence of cocaine, Cardarelli drafted the affidavit and obtained a search warrant from a state court judge. At approximately 8:00 p.m. on July 30, Cardarelli and other officers executed the search warrant at the Carty residence.

Detective Stephen Berarducci corroborated Cardarelli's testimony. He testified that he saw Cardarelli at the SIB office on July 30 at about 2:00 p.m. and was aware that Cardarelli was going to attempt a controlled buy at the Carty residence. According to Berarducci, Cardarelli returned to the office around 4:00 p.m. and performed a field test on a small plastic bag of cocaine, which Cardarelli said had been purchased at the Carty residence. Berarducci also testified that he received a check the following day from Sergeant Dennis Lambert, the SIB evidence control officer, which was used to pay for the informant's services. A photocopy of the check was admitted into evidence.

Sergeant Lambert testified that he could locate neither a log book entry, nor a "controlled buy form," reflecting a drug transaction on July 30 conducted by Detective Cardarelli or any other officer.3 Lambert testified that his records documented a controlled buy of heroin on July 25 or 26 at the apartment building in which Carty lived, but that it occurred on the second floor of the building and was unrelated to any controlled buy at the Carty apartment on the first floor.

Two of Carty's co-workers testified that he was at work on July 30 between 9:00 a.m. and 7:00 p.m. Mrs. Carty provided similar testimony and submitted receipts reflecting Carty's wages for the day. She further testified that no one came to their residence between 2:00 p.m. and 4:00 p.m. on July 30. Two other individuals testified that they were at the Carty residence throughout the day on July 30 and that no one came to the house between 2:00 p.m. and 4:00 p.m.

At the conclusion of the suppression hearing, the district court declined to suppress the evidence seized pursuant to the warrant as Carty had failed to produce sufficient evidence to undermine the Cardarelli affidavit.4 Carty contends that he demonstrated that the controlled buy could not have occurred as described in the Cardarelli affidavit. Without the false statements, he argues, the affidavit was insufficient to establish probable cause. See Franks, 438 U.S. at 156, 98 S.Ct. at 2676 (If the defendant proves perjury or "reckless disregard," by a preponderance of the evidence, and the untainted content of the affidavit is insufficient to establish probable cause, the fruits of the search must be excluded "to the same extent as if probable cause was lacking on the face of the affidavit.").

We review the district court's findings of fact for clear error; its conclusion of law de novo. United States v. Garcia, 983 F.2d 1160, 1167 (1st Cir.1993) (citing United States v. Sanchez, 943 F.2d 110, 112 (1st Cir.1991)). Its denial of the suppression motion will be upheld if supported by any reasonable view of the evidence. Id.

Although we find it troubling, as did the district court, that there is no record of a controlled cocaine buy during the entire relevant period, our review of the suppression hearing transcript reveals nothing inherently contradictory or incredible in Cardarelli's testimony, as corroborated by Detective Berarducci. First and foremost, Cardarelli's suppression hearing testimony as to the exact date of the controlled buy (July 30) is not inconsistent with the time period ("within the past few days") he gave in the warrant affidavit; July 30 at 2:00 to 4:00 p.m. was "within the past few days" of Cardarelli's preparation of the warrant affidavit, which occurred late in the afternoon or early in the evening of July 30. Thus, the affidavit was not necessarily inconsistent with Cardarelli's testimony. Second, the district court, before whom Cardarelli and Berarducci testified, credited Cardarelli's explanation that it was customary to avoid precise specification of the dates of controlled buys in order to protect the identity of informants. Finding nothing inherently inconsistent in Cardarelli's testimony, and mindful of the trial court's superior vantage point, we are satisfied that there is no sound basis for second-guessing its demeanor-based credibility determinations at the suppression hearing.5 See Wainwright v. Witt, 469 U.S. 412, 428, 105 S. Ct. 844, 854, 83 L. Ed. 2d 841 (1985) (determinations of demeanor and credibility are peculiarly within a trial judge's province); United States v. Portalla, 985 F.2d 621, 622 (1st Cir.1993) (recognizing district court's broad power to determine witness credibility); see also Anderson v. Bessemer City, 470 U.S. 564, 575, 105 S. Ct. 1504, 1512, 84 L. Ed. 2d 518 (1985) ("only the trial judge can be aware of the variations in demeanor and tone of voice that bear so heavily on the listener's understanding of and belief in what is said").6

Carty next asserts that his Sixth Amendment right to confront adverse witnesses was infringed by the district court's restrictions on cross-examination of Detective Cardarelli at the suppression hearing. In the course of cross-examining Cardarelli about the perceived discrepancy between his testimony and his affidavit relating to the date of the controlled buy, defense counsel inquired: "Tell me, Detective Cardarelli, why are you represented by Mr. Bevilacqua?" When the court refused, on relevancy grounds, to direct Cardarelli to answer over the government's objection, defense counsel responded by way of an offer of proof: "[I]t is my belief that this witness is being investigated for corruption in the police department." Defense counsel hypothesized that Cardarelli may have adjusted the asserted date of the controlled buy to negate Carty's alibi evidence. Counsel argued that the proposed line of questioning was intended to determine whether Cardarelli was telling the truth. Rebuffed by the district court,7 defense counsel urged that he be permitted to show Cardarelli's bias, suggesting that "if, in fact, the investigation is being conducted ... by the [f]ederal [g]overnment, then [Cardarelli] has an interest in making the [f]ederal [g]overnment happy by being a witness who testifies consistently with the [g]overnment's theory of this case[, a]nd bias to that extent is a legitimate area of inquiry." Concluding that it was not "material to the issue here," the court remained steadfast in its refusal to permit inquiry concerning the supposed investigation.

Carty contends that the proffer demonstrated that the putative federal investigation into possible corruption involving Cardarelli was directly related to the events in the case and probative of Cardarelli's credibility and bias, and, therefore, that the district court's ruling deprived him of his Sixth Amendment right to confrontation. "[A] primary interest secured by [the Confrontation Clause of the Sixth Amendment] is the right of cross-examination." Douglas v. Alabama, 380 U.S. 415, 418, 85 S. Ct. 1074, 1076, 13 L. Ed. 2d 934 (1965). Cross-examination is the "principal means by which the believability of a witness and the truth of his testimony are tested." Davis v. Alaska, 415 U.S. 308, 316, 94 S. Ct. 1105, 1110, 39 L. Ed. 2d 347 (1974). Nevertheless, the right of cross-examination is not without limits. "On the contrary, trial judges retain wide latitude insofar as the Confrontation Clause is concerned to impose reasonable limits on ... cross-examination based on concerns about, among other things, harassment, prejudice, confusion of the issues, the witness' safety, or interrogation that is repetitive or only marginally relevant." Delaware v. Van Arsdall, 475 U.S. 673, 679, 106 S. Ct. 1431, 1435, 89 L. Ed. 2d 674 (1986). See Brown v. Powell, 975 F.2d 1, 3-4 (1st Cir.1992); United States v. Malik, 928 F.2d 17, 19-20 (1st Cir.1991); United States v. Rivera-Santiago, 872 F.2d 1073, 1084 (1st Cir.), cert. denied, 492 U.S. 910, 109 S. Ct. 3227, 106 L. Ed. 2d 576 (1989) and cert. denied, 493 U.S. 832, 110 S. Ct. 105, 107 L. Ed. 2d 68 (1989). We review district court limitations on cross-examination for "abuse of discretion." United States v. Boylan, 898 F.2d 230, 254 (1st Cir.), cert. denied, 498 U.S. 849, 111 S. Ct. 139, 112 L. Ed. 2d 106 (1990); Rivera-Santiago, 872 F.2d at 1084.

A criminal defendant's right to cross-examine for bias is an important component of the constitutional right to confrontation. Thus, the trial court may not limit cross-examination in this area without according the defendant the latitude to conduct a "minimum threshold of inquiry" sufficient to permit the factfinder to make the requisite discriminating appraisal of the biases of the witness. Brown, 975 F.2d at 5 (quoting United States v. Jarabek, 726 F.2d 889, 902 (1st Cir.1984)); United States v. Kepreos, 759 F.2d 961, 965 (1st Cir.), cert. denied, 474 U.S. 901, 106 S. Ct. 227, 88 L. Ed. 2d 227 (1985); United States v. Tracey, 675 F.2d 433, 437 (1st Cir.1982). Otherwise, the defendant's right to confrontation will have been infringed unless the factfinder nonetheless possessed "sufficient other information ... to make a discriminating appraisal of the possible biases and motivations of the witness[ ].' " Brown, 975 F.2d at 5 (quoting Tracey, 675 F.2d at 437).

On the record in this case, we conclude that the district court acted well within its discretion in declining to permit cross-examination to proceed after considering the offer of proof. The court recognized that the conclusory offer of proof simply speculated that an investigation into possible police corruption might be underway and might involve Cardarelli. There was no indication as to the source or basis of the stated belief, no substantiation, and no representation that the federal government was involved in any such investigation. Nor was there any suggestion that the supposed investigation in any manner related to the events at issue in this case. Thus, the contention, advanced below and on appeal, that Cardarelli may have testified with a view to impressing the federal government is not even based on a speculative belief. Absent any such logical linkage, the proposed inquiry was irrelevant, just as the district court found. Moreover, as the district court was also the finder of fact at the suppression hearing, the defense was on notice that it needed to make the strongest offer of proof possible to overcome the government's objection to this line of inquiry. Yet the offer of proof was left (and remains) patently deficient to enable the conclusion that the district court abused its discretion by ruling the proffer inadequate to warrant further inquiry over the government's objection. Cf. United States v. Sutherland, 929 F.2d 765, 776-77 (1st Cir.) (limitation on cross-examination of witness did not contravene Sixth Amendment right to confrontation where defendant "demonstrated absolutely no basis for suspecting bias other than a conclusory allegation" that the witness hoped to receive favorable treatment from the government in exchange for his testimony), cert. denied, --- U.S. ----, 112 S. Ct. 83, 116 L. Ed. 2d 56 (1991); Fed.R.Evid. 103(a)(2). We find no Sixth Amendment violation.

Finally, Carty contends that the trial court committed reversible error by admitting "other act" evidence which should have been excluded under Federal Rule of Evidence 404(b) or 403. The challenged evidence consisted of post-arrest admissions by appellant Carty relating to a drug source. At trial, Detective Cardarelli testified as follows:

Mr. Carty stated to me that he also had a location on Route 95 in Attleboro where he would drive his white Camaro to meet a so-called person, he didn't mention any name or didn't give any description, at a road side rest stop where this person would meet him and leave drugs underneath a trash container at that roadside stop and he would retrieve the drugs and bring them back to the City of Providence. And I then asked him why did you go through all that trouble? And he says, because this person does not want to come into the City of Providence because there's a lot of heat on drug activity in the City of Providence.

Another police officer testified that he overheard the conversation, and corroborated Cardarelli's testimony. When asked whether Carty described what he was buying, the officer replied, "coke."

Admissible "other act" evidence must survive scrutiny under Rules 403 and 404(b). First, under the "absolute bar" of Rule 404(b), the evidence is inadmissible if relevant solely to show the defendant's character or propensity for criminal conduct; it must have some "special relevance" to a material issue such as motive, opportunity, intent, preparation, plan, or knowledge. See United States v. Agudelo, 988 F.2d 285, 287 (1st Cir.1993); United States v. Williams, 985 F.2d 634, 637 (1st Cir.1993); United States v. Donovan, 984 F.2d 507, 512 (1st Cir.1993). Second, under Rule 403, the trial court must satisfy itself that the probative value of the evidence is not substantially outweighed by the danger of unfair prejudice, confusion, or undue delay. See Agudelo, 988 F.2d at 287; Donovan, 984 F.2d at 512; United States v. Devin, 918 F.2d 280, 286 (1st Cir.1990). The admissibility of "other act" evidence is committed to the sound discretion of the district court, and we review its ruling only for abuse of discretion, United States v. Garcia, 983 F.2d 1160, 1172 (1st Cir.1993), bearing in mind that Rule 404(b) is a rule of inclusion, not exclusion, see Donovan, 984 F.2d at 512; United States v. Fields, 871 F.2d 188, 196 (1st Cir.), cert. denied, 493 U.S. 955, 110 S. Ct. 369, 107 L. Ed. 2d 355 (1989).

a. Fed.R.Evid. 404(b)

Notwithstanding defense counsel's plaint that the testimony indicated that Carty was buying rather than distributing drugs, the district court admitted the challenged evidence on the ground that it "goes to the possible intent and shows that [Carty] was one who did distribute or planned to distribute." Carty contends that the district court improperly ascribed "special relevance" to the evidence.

The court correctly ruled that the evidence was probative of intent to commit the charged offense of possession with intent to distribute, noting that "you have to buy [cocaine] to sell it." See, e.g., Garcia, 983 F.2d at 1173 (prior arrest for dealing in cocaine admissible to show intent to possess and distribute cocaine) (quoting United States v. Hadfield, 918 F.2d 987, 994 (1st Cir.1990) (citing cases)). The evidence was probative of opportunity as well. Thus, since the "other act" evidence permitted at least one relevant non-propensity and non-character based inference, see United States v. Nickens, 955 F.2d 112, 124 (1st Cir.), cert. denied, --- U.S. ----, 113 S. Ct. 108, 121 L. Ed. 2d 66 (1992), it satisfied the requirements of Rule 404(b).

b. Fed.R.Evid. 403

Appellant contends that the probative value of the evidence was greatly outweighed by its prejudicial effect, as the government did not link the "other act" evidence to the cocaine seized from Carty's garage, nor did it establish the quantity previously purchased or show that it was part of a continuing scheme or conspiracy.

Only in exceptional circumstances will we reverse a trial court's evidentiary ruling in the face of a Rule 403 challenge. Garcia, 983 F.2d at 1173; United States v. Garcia-Rosa, 876 F.2d 209, 221 (1st Cir.1989), cert. denied, 493 U.S. 1030, 110 S. Ct. 742, 107 L. Ed. 2d 760 (1990). Appellant has not shown that the probative value of the "other act" evidence was substantially outweighed by its unfair prejudice. See Onujiogu v. United States, 817 F.2d 3, 6 (1st Cir.1987) ("The fact that a piece of evidence hurts a party's chances does not mean it should automatically be excluded, [or] there would be precious little left in the way of probative evidence in any case"). As Carty's post-arrest statements relating to a cocaine source were probative of his intent and opportunity to possess and distribute cocaine, see supra Part I.B.1.a., and there was no "unfair prejudice,"8 Rule 403 posed no barrier to their admission in evidence.9

Affirmed.

Dissent follows.

TORRUELLA, Circuit Judge (Dissenting).

I dissent because the so-called "other act" evidence relating to a drug source unconnected to the facts of the present case and admitted under Federal Rules of Evidence 404(b), is nothing more than improper propensity or character evidence. I disagree with my colleagues in the majority that it is "far-fetched" that this evidence influenced the jury in any way because Carty was acquitted of the cocaine charge. Ante, at 1009 n. 9. The objected evidence branded him as a drug dealer, not necessarily as the possessor of the small amount of cocaine found. As such a nefarious person, the jury could very well have believed that the firearms were his tools of the trade. The improper character evidence easily could have carried the day for the Government, considering the highly contradictory nature of the proof it presented. Ante, at 1004-1005. In view of the constitutional burden required of the Government in a criminal case, I fail to see why all the speculation regarding what the jury did or did not do with this improper evidence, should be weighted against defendant.

Appellant should be granted a new trial.