(Dissenting).
To accommodate a minor inconvenience in the presentation of evidence by the government, the majority allows a major incursion into a criminal defendant’s Sixth Amendment right to confrontation.1 This unfortunate outcome is the result of allowing so-called “expert” testimony contrary to the requirements of Federal Rule of Evidence 702. The majority goes further astray by failing to call upon the government to make an adequate showing of reasonable reliance under Federal Rule of Evidence 703. This regrettable development is especially egregious where, as *93here, the “experts in the particular field” are federal law enforcement officers testifying regarding a self-serving subject matter. Finally, the majority simply fails to take into account the fact that the use of hearsay evidence in a criminal case must pass constitutional muster. The Supreme Court has held that hearsay evidence must possess “particularized guarantees of trustworthiness,” Ohio v. Roberts, 448 U.S. 56, 66, 100 S.Ct. 2531, 65 L.Ed.2d 597 (1980), such that “adversarial testing would be expected to add little, if anything, to [its] reliability,” Lilly v. Virginia, 527 U.S. 116, -, 119 S.Ct. 1887, 1894, 144 L.Ed.2d 117 (1999). I fail to see how the hearsay evidence objected to in this appeal meets this high standard, particularly when we consider that this evidence was used to establish a jurisdictional fact absent which there is no triable federal crime.
In addition, the Court’s deference to the ATF is unwarranted as a matter of policy. The improper use of the tendered testimony serves no justifiable purpose. The prosecution could easily establish the interstate nexus of a firearm by introducing records subpoenaed from the manufacturer, direct testimony from the manufacturer, or even ATF trace reports. This would require only a minimal expenditure by the government and relatively little effort on the part of the prosecution. In an industry where governmental oversight is endemic and record keeping is pervasive, it should not be unduly burdensome to require that such independent evidence be produced rather than to rely, as proof of a jurisdictional element of the crime charged, on self-serving “ATF research” material.
DISCUSSION
Alvin Scott Corey was charged with possession of a firearm by a felon in violation of 18 U.S.C. § 922(g)(1). The statute states that:
It shall be unlawful for any person— who has been convicted in any court of, a crime punishable by imprisonment for a term exceeding one year .... to ship or transport in interstate commerce or foreign commerce, or possess in or affecting commerce, any firearm or ammunition; or to receive any firearm or ammunition which has been shipped in interstate or foreign commerce.
18 U.S.C. § 922(g)(1).
At issue in this appeal is the evidence offered by the prosecution to establish the interstate nexus prong of § 922(g)(1) — “in or affecting commerce.” The interstate nexus prong of § 922(g)(1) is a jurisdictional requirement. Compare U.S. v. Blais, 98 F.3d 647, 648-50 (1st Cir.1996) (holding facial challenge to the constitutionality of 18 U.S.C. § 922(g)(1) is hopeless as a matter of law), with United States v. López, 514 U.S. 549, 562, 115 S.Ct. 1624, 131 L.Ed.2d 626 (1995) (holding 18 U.S.C. § 922(q) unconstitutional because it “contains no jurisdictional element which would ensure, through case-by-case inquiry, that the firearm possession in question affects interstate commerce”). It is well settled that proof that a firearm was manufactured outside the state in which the possession occurred is sufficient to support a finding that the possession was “in or affected commerce.” See, e.g., United States v. Gourley, 835 F.2d 249, 251 (10th Cir.1987); United States v. Johnson, 722 F.2d 407, 410 (8th Cir.1983).
In this case, the prosecution offered the testimony of ATF Agent Michael Cooney to establish that the weapon in Corey’s possession at the time of his arrest in Maine had been manufactured either in Massachusetts or Ohio, and therefore had traveled in interstate commerce. The court admitted this testimony over defendant’s objection pursuant to Fed.R.Evid. 703. Rule 703 allows an expert to give opinion testimony that is based on facts or data not admitted into evidence if “of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject.”
*941. Standard of Review
We review a trial court’s rulings admitting or excluding particular evidence for abuse of discretion. See, e.g., United States v. Riverar-Gómez, 67 F.3d 993, 997 (1st Cir.1995). Accordingly, as the majority correctly indicates, a district court’s decision to admit or exclude expert testimony is generally entitled to great deference. See General Elec. Co. v. Joiner, 522 U.S. 136, 138-39, 118 S.Ct. 512,139 L.Ed.2d 508 (1997); United States v. Shay, 57 F.3d 126, 132 (1st Cir.1995). However, unlike most appeals involving the admissibility of expert testimony, this case does not present a pure evidentiary question. Here, the trial court allowed the prosecution to rely solely on expert testimony to establish the jurisdictional element of the crime. See López, 514 U.S. at 562, 115 S.Ct. 1624; Raymond, 98 F.3d at 648-50. Under these circumstances, a less deferential standard of review is appropriate.
[W]hile many courts make the general statement that a trial court’s rulings on evidence are discretionary, it is clear that many particular evidence determinations raise a question beyond that application and may be considered questions of law. The abuse of discretion standard recited by reflex should not stop the appellate court from freely performing its own institutional role of deciding what the law is.
Steven Childress & Martha Davis, Federal Standards of Review § 4.02 (1992). The Fifth Circuit is in agreement and has held that expert testimony may be subject to closer examination.
Since the adoption of the Federal Rules of Evidence in 1975, we have accorded trial courts considerable discretion in determining the admissibility of opinion evidence by experts. We have said that the discretion is “broad” and that the determination of admissibility should be sustained “unless manifestly erroneous.” This deference reflects the superior opportunity of the trial judge to gauge both the competence of the expert and the extent to which his opinion would be helpful to the jury. Despite the seeming breadth of the language we have used to describe this deference, trial court rulings regarding the admission of expert testimony remain reviewable. We have not left all such decisionmaking to trial judges, nor should we.
Basic policy questions that affect the very nature of a trial lie behind decisions to receive expert testimony. Under the Federal Rules of Evidence, experts not only explain evidence, but are themselves sources of evidence. These two roles, though related, are quite distinct. In deciding whether explanation by an expert will assist the jury or judge, the superior position of the trial judge over the appellate judge is apparent. By comparison, in deciding whether evidence should be allowed from this source, the trial judge draws less upon the scene and the cast immediately before him, and more upon the substantive law. To the extent that the decision to allow expert testimony as a source of evidence is significantly intertwined with the underlying substantive law, we will accord it less deference, and take a much closer look.
In re Air Crash Disaster at New Orleans, 795 F.2d 1230, 1233 (5th Cir.1986). Similarly, in Salas v. Carpenter, 980 F.2d 299 (5th Cir.1992), the Fifth Circuit held: “Expert witnesses may perform two roles: explaining evidence to a jury, and acting as the source of evidence for a jury. When the expert speaks in the latter role, we give less deference to a district court’s admissibility decision.” Id. at 305.2
*95Here, Agent Cooney was the sole source of the prosecution’s evidence on interstate nexus, and the question before this Court is whether the trial court’s ruling admitting this testimony was proper as a matter of law. Accordingly, in line with the Fifth Circuit’s reasoning in Pan American World Airways and Salas, I would hold that the trial court’s decision to allow expert testimony as proof of the jurisdictional element of § 922(g)(1) is subject to a higher standard of review.
Nonetheless, my dissent does not rest on this point. I may assume, arguendo, that the applicable standard of review is abuse of discretion. Applying this standard, it is settled that the Court may only reverse appellant’s conviction on the “evi-dentiary question” raised in this case if: (1) the district court based its decision on an incorrect legal standard; or (2) we have a “definite and firm conviction that the court made a clear error of judgment in the conclusion it reached based upon a weighing of the relevant factors.” Shay, 57 F.3d at 132 (quoting United States v. Benavente Gómez, 921 F.2d 378, 384 (1st Cir.1990)).
II. Question of First Impression
Whether expert testimony may be used to establish the jurisdictional requirement of § 922(g)(1) is a question of first impression in the First Circuit. However, at least seven other circuits have addressed this issue. Relying on either Fed. R. Evid 702 or 703, all have determined that expert testimony is permissible. See, e.g., United States v. Gresham, 118 F.3d 258, 266 (5th Cir.1997); United States v. Maddix, 96 F.3d 311, 315 (8th Cir.1996); United States v. Coleman, 22 F.3d 126, 130-31 (7th Cir. 1994); United States v. Dunn, 946 F.2d 615, 618 (9th Cir.1991); United States v. Bonavia, 927 F.2d 565, 567 n. 2 (11th Cir.1991); United States v. Gregg, 803 F.2d 568, 571 (10th Cir.1986); United States v. Simmons, 773 F.2d 1455, 1460-61 (4th Cir.1985). Unlike my colleagues in the majority, I believe that this case law is, at least in part, contrary to the dictates of Rules 702 and 703. Further, the cases are distinguishable on the facts. More importantly, however, compliance with Rule 703 alone is not sufficient to uphold appellant’s conviction in this case because the evidence does not satisfy the requirements of the Sixth Amendment. Accordingly, for the reasons stated below, I would reverse appellant’s conviction.
III. Federal Rule of Evidence 702
To be admissible, expert testimony must meet the requirements of Fed.R.Evid. 702. It provides:
If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.
Fed.R.Evid. 702. The rule has three requirements, but I need only address the two that are at issue in this appeal. First, the subject matter of the testimony must involve “scientific, technical, or other specialized knowledge.” Id. Second, a witness may testify as an expert only where the court determines that “specialized knowledge will assist the trier of fact to understand the evidence.” Id. (emphasis added).
In this case, the prosecution used Agent Cooney’s expert testimony for three purposes: (1) to identify Smith & Wesson as the manufacturer of the shotgun in Corey’s possession, (2) to identify the location of each of the Smith & Wesson manufacturing plants, and (3) to identify which of the three potential Smith & Wesson facilities actually manufactured this particular shotgun. Expert testimony regarding the identity of a firearm manufacturer is proper because it requires specialized knowledge that undoubtedly assists the jury. However, neither the location of a manufacturing plant nor the actual place a firearm is manufactured fall within the parameters of Rule 702 because neither can *96fairly be described as “specialized knowledge.” Id.
The majority reaches an opposite conclusion without analysis. The Rule 702 case law, however, does not clearly support the majority’s holding. In contrast, a careful examination of the law illustrates why Agent Cooney’s testimony does not constitute “specialized knowledge [that] will assist the trier of fact to understand the evidence.” Id.
The first case to consider the admissibility of expert testimony on the interstate nexus of a firearm was United States v. Gann, 732 F.2d 714, 724 (9th Cir.1984). In Gann, the defendant argued that the district court erred in denying his objection to the testimony offered by the government’s expert witness, an ATF firearms enforcement officer, as to his opinion of the location of the manufacturer of the recovered firearms and ammunition. See id. at 724. The defendant’s principal argument was that proof of the location of a manufacturing plant does not require expert testimony.
The Ninth Circuit affirmed the conviction pursuant to Fed.R.Evid. 702. In reaching this holding, the court cited United States v. Sickles, 524 F.Supp. 506, 512 (D.Del.1981), aff'd, 688 F.2d 827 (3d Cir. 1982). In Sickles, the district court held that the admission of expert testimony relating to the location of the manufacturing plant was proper. The court reasoned that the expert witness relied on information on the gun itself, as well as treatises and the officer’s experience. Under these circumstances, “the ultimate decision of whether the guns traveled in interstate commerce was for the jury, and [the] expert was only drawing on common sense when he opined on [the] ultimate issue.” Id. However, the Ninth Circuit stated that the expert in Gann testified “not for the purpose of identifying the location of weapon and ammunition manufacturing plants, but instead for the purpose of establishing the particular manufacturer of each of the weapons and ammunition seized.” Gann, 732 F.2d at 724 (emphasis added). “Based on his expert knowledge,” the agent “identified the manufacturer from characteristic shell markings and stamps.” Id. The Ninth Circuit determined “[t]his testimony was relevant to prove that the objects had traveled in interstate commerce.” Id.
The holding in Gann is correct, but the opinion — lacking any real analysis — is a source of confusion which infects this area of law. As indicated, Gann holds that under Rule 702 expert testimony may be used to identify the particular manufacturer of a weapon. See id. at 724. The language of Rule 702 clearly supports this conclusion: “If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence ..., a witness qualified as an expert ... may testify thereto.” Fed.R.Evid. 702. There is no question that the average lay juror cannot identify the manufacturer of a firearm simply by examining the weapon. This is especially true in the case of an unmarked gun or a gun marked only with a serial number. Consequently, testimony identifying the manufacturer of a firearm will usually constitute technical or specialized knowledge that will assist the trier of fact. Rule 702 requires no more.
The problem with Gann is that it cites with approval United States v. Sickles. In Sickles, the district court held that expert testimony could be used to identify the location of a manufacturing plant. See Sickles, 524 F.Supp. at 512. This is an entirely different proposition, and one that has no basis in Rule 702.
The location of a manufacturing plant is a question of fact that may be established by direct evidence. The prosecution, for example, could introduce any number of corporate documents or historical records to establish the location of a corporation’s manufacturing facilities. Similarly, direct testimony from the manufacturer could easily be used in the place of so-called expert testimony. Unlike the identity of a firearm manufacturer, the location of a manufacturer’s facilities simply does not involve “scientific, technical, or other specialized knowledge.” Fed.R.Evid. 702.
*97The facts of this case are illustrative. Here, Agent Cooney testified that Smith & Wesson has manufacturing facilities in Massachusetts, Ohio, and Maine. Massachusetts, Ohio, and Maine are not “scientific, technical, or other specialized knowledge.” Id. Compare, for example, testimony that Smith & Wesson has a manufacturing plant in Massachusetts with expert testimony involving aircraft maintenance,3 accounting practices,4 banking customs,5 corporate management,6 farm production,7 motion picture distribution,8 securities investments,9 or the meaning of criminal jargon.10 By comparison, the location of a Smith & Wesson production plant is .an ordinary fact that is subject to the presentation of evidence in the same way as any other disputed fact. Admittedly, a juror is not likely to have independent knowledge of where Smith & Wesson has production facilities, but this alone does not make the location of the plants technical or specialized. If it did, Rule 702 would be meaningless, and expert testimony could be used to establish essentially any fact in dispute in every case.
In addition, Rule 702 requires that the testimony “assist the trier of fact.” Fed. R.Evid. 702 (emphasis added). Here, an ordinary juror is abundantly qualified to properly assess direct evidence of a physical location. It is patently disingenuous to suggest that the trier of fact requires the assistance of expert testimony to understand basic corporate documents or direct testimony from a manufacturer indicating where the company has manufacturing facilities. This is a matter easily evaluated by laymen within the realm of their common knowledge and experience.
Similarly, the actual place of manufacture (i.e., where the shotgun in Corey’s possession was in fact manufactured) does not fall within the standard of Rule 702.11 A juror does not require expert testimony to understand corporate records indicating that a firearm was manufactured in either Massachusetts or Ohio, but not Maine. This is a fact that people of common understanding can easily comprehend. Consequently, contrary to the majority’s indication, there is overwhelming authority that this is not a proper subject for expert testimony. See Fed.R.Evid. 702 advisory committee’s note (“There is no more certain test for determining when experts may be used than the common sense inquiry whether the untrained layman would be qualified to determine intelligently and to the best possible degree the particular issue without enlightenment from those having a specialized understanding of the subject involved in the dispute.”).12
Nonetheless, the few cases that have addressed this question have determined that expert testimony regarding the interstate nexus of a firearm is permissible under Rule 702. See United States v. Dunn, 946 F.2d 615, 618 (9th Cir.1991); *98United States v. Ware, 914 F.2d 997, 1002 (7th Cir.1990). These cases, however, uniformly rely on Gann, erroneously citing it as authority for rejecting all Rule 702 challenges to expert testimony on this issue. See id. The majority, in turn, finds sufficient support in these cases to reject appellant’s Rule 702 challenge to his conviction without analysis. I respectfully believe this determination is erroneous. Quite simply, as indicated above, the language of Rule 702 supports appellant’s argument and belies the holding of the Court.13
IV. Federal Rule of Evidence 703
I also disagree with my colleagues’ treatment of Rule 703. Rule 703 provides:
The facts or data in the particular case upon which an expert bases an opinion *99or inference may be those perceived by or made known to the expert at or before the hearing. If of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject, the facts or data need not be admissible in evidence.
Fed.R.Evid. 703 (emphasis added). Accordingly, the proponent of expert testimony must make two showings under Rule 703. First, the party offering the expert testimony must show that the expert relied on facts or data of the type relied upon by experts in the field. Second, the party must show that this reliance was reasonable.14 The latter is the critical element in this case.
Here, we must decide whether Agent Cooney’s testimony was based on facts or data of a type reasonably relied upon by experts in the field in forming an opinion as to the interstate nexus of a firearm. Appellant argues that the trial court erred in admitting Agent Cooney’s testimony because his opinion was based entirely on hearsay evidence. The majority concludes that Agent Cooney’s testimony was proper because he relied not only on a phone call to Smith & Wesson historian Roy Jinks, but also on ATF “in-house technical information” and his own “knowledge and experience.” I respectfully disagree with this analysis.
A. The Evidence Relied on by Agent Cooney Was Not Reasonable under Rule 703
As stated, Agent Cooney telephoned Smith & Wesson historian Roy Jinks to *100inquire about the origin of appellant’s shotgun. The majority believes that this reliance on hearsay is irrelevant since Agent Cooney also relied on ATF in-house technical files and his personal experience. I disagree and would hold that the government’s evidence of interstate nfexus is insufficient pursuant to Rule 703.
While the majority declines to reach the propriety of the telephone call, it seems intuitive that information gleaned from a phone call placed by an investigating officer after criminal proceedings have begun does not bear objective earmarks of reasonable reliability. For example, the information provided by Mr. Jinks was not published, documented, or subject to peer review. Further, we have no way of knowing on what basis Mr. Jinks determined that the Smith & Wesson shotgun in appellant’s possession was not manufactured in Maine. At best, the testimony regarding the telephone conversation amounts to a summary of another expert’s opinion. This alone is not sufficient for admission under Rule 703. See, e.g., TK-7 Corp. v. Estate ofBarbouti, 993 F.2d 722, 732 (10th Cir.1993) (expert testimony was inadmissible under Rule 703 “where the expert failed to demonstrate any basis for concluding that another individual’s opinion ... was reliable, other than the fact that it was the opinion of someone he believed to be an expert”); United States v. Smith, 869 F.2d 348, 355 (7th Cir.1989) (“[A]n expert witness may not simply summarize the out-of-court statements of others as his testimony.”); see also 29 Charles Alan Wright & Victor James Gold, Federal Practice and Procedure § 6274 (1997).
Accordingly, we are left with the ATF in-house files and the agent’s personal experience. Admittedly, both may be relevant factors in a Rule 703 analysis. However, I am aware of no case where the expert relied only on ATF reference materials and his personal experience. In most cases that indicate a reliance on “personal research,” the expert testimony was also based on an examination of the weapon. See United States v. Gresham, 118 F.3d 258, 266 (5th Cir.1997); United States v. Horsman, 114 F.3d 822, 826 (8th Cir.1997); United States v. Maddix, 96 F.3d 311, 315 (8th Cir.1996); United States v. Bonavia, 927 F.2d 565, 567 n. 2 (11th Cir.1991); United States v. Ware, 914 F.2d 997, 1002 (7th Cir.1990); United States v. Wallace, 889 F.2d 580, 584 (5th Cir.1989). More important, the research itself included “corporate literature,” Gresham, 118 F.3d at 266, “reference books,” Bonavia, 927 F.2d at 567 n. 2, “various firearms trade books, magazines, and reference materials,” Ware, 914 F.2d at 1002, “ATF publications,” id. (emphasis added), “catalogs, firearms manuals, and reference publications,” United States v. Clawson, 831 F.2d 909, 912 (9th Cir.1987), or at the very least an ATF trace report, see Maddix, 96 F.3d at 315.
In contrast to these traditional and well-accepted forms of research, Agent Cooney relied on in-house material generated by the ATF itself. Cooney refers to these materials as ATF “research libraries” and “technical files.” Removing this semantic gloss, the underlying picture is troubling: a federal law enforcement officer relied on internal, non-published government files to establish an element of appellant’s crime. In my opinion, this cannot amount to reasonable reliance by definition and therefore violates Rule 703. It is difficult to imagine that in any other context the Court would allow an agent of one party to rely on that party’s own self-serving, internal documents as a basis for his so-called expert opinion.
Further, when asked how the ATF in-house information was generated, Agent Cooney explained that ATF research materials are compiled by ATF agents through interviews with firearm manufacturers. At one point, for example, he states:
That’s in-house generated information that we get from the factory, from brochures, from someone speaking with the factory prior to my calling them.
*101In fact, when defense counsel asked whether the information relied on by Agent Cooney depended on conversations with Smith & Wesson employees, Cooney replied, “[h]ow else would I find that information out?” Consequently, appellant’s contention that Agent Cooney’s testimony was based entirely on hearsay is absolutely correct. As indicated, Rule 703 requires reasonable reliance, and I do not believe that a law enforcement officer may reasonably rely on hearsay evidence to establish an element of a crime simply because he is deemed an expert witness.
Similarly, Agent Cooney’s purported reliance on personal experience is not persuasive. Three courts have allowed firearms experts to rely solely on their personal experience in formulating an opinion as to interstate nexus. See United States v. Buggs, 904 F.2d 1070, 1077 (7th Cir.1990); Gregg, 803 F.2d at 571; Simmons, 773 F.2d at 1460-61. These cases, however, are premised on very different facts than those contained in this case. Specifically, in each of these cases the expert testimony was limited to a statement that there were no manufacturing facilities in the state of possession. See Buggs, 904 F.2d at 1077 (ATF agent testified that “Smith & Wesson handguns are manufactured in Springfield, Massachusetts. He also testified that a .357 magnum is a revolver and no revolvers are manufactured within Indiana’s borders.” (emphasis added)); Gregg, 803 F.2d at 571 (weapon specialist testified “that there were no major gun manufacturers in State of Oklahoma”); Simmons, 773 F.2d at 1460-61 (ATF agent testified “based on his personal knowledge and experience, the Savage Arms Co. had never had a manufacturing plant in Maryland.”). In other words, courts have allowed firearms experts to rely on their personal experience only where based on the brand it was a physical impossibility that the weapon was manufactured in the state of possession. Here, Smith & Wesson has a manufacturing plant in Maine, the state of possession. Under these circumstances, it is axiomatic that a higher degree of proof should be required to opine that appellant’s Smith & Wesson firearm was not manufactured at the Smith & Wesson plant in Maine.
B. Agent Cooney Did Not Rely on Distinctive Markings on the Firearm
The majority overlooks the fact that Agent Cooney did not rely on distinctive markings on Corey’s shotgun in formulating his opinion.15 An overwhelming majority of the reported cases indicate that markings on a firearm are a central factor in a Rule 703 analysis. See, e.g., Gresham, 118 F.3d at 266; Horsman, 114 F.3d at 824; Maddix, 96 F.3d at 315; Coleman, 22 *102F.3d at 130-31; Ware, 914 F.2d at 1002; Wallace, 889 F.2d at 584; United States v. Merritt, 882 F.2d 916, 920 (5th Cir.1989); United States v. Gourley, 835 F.2d 249, 251 (10th Cir.1987); United States v. Harper, 802 F.2d 115, 121 (5th Cir.1986). The importance of distinctive markings on a firearm is self evident: markings are non-hearsay evidence that allow an expert to identify the manufacturer. Once the manufacturer is identified, the expert can easily determine the location of the manufacturing facilities. Typically these facilities are outside of the state of possession, and therefore the expert can readily opine that the weapon traveled in interstate commerce.
United States v. Maddix is illustrative. On March 11,1994 Maddix was arrested in Kansas City, Missouri and charged with being a felon in possession of a firearm in violation of § 922(g)(1). See 96 F.3d at 313. At trial, an ATF special agent testified that the revolver in Maddix’s possession had been manufactured in California, shipped to dealers in Arkansas, and then eventually sold in Missouri. See id. at 315. Based on this testimony, Maddix was convicted as charged.
On appeal, Maddix argued that the district court abused its discretion in admitting hearsay evidence to establish the jurisdictional element of § 922(g)(1). The Eighth Circuit, however, affirmed. The court reasoned that the special agent testified as a firearms expert and that his opinion properly relied on a tracing report and markings on the weapon. The court stated, “firearms experts customarily rely upon tracing reports to determine whether firearms have been transported across state lines.” Id. at 315 (citing Fed.R.Evid. 703). Further, “[h]is opinion was also based upon evidence other than the tracing report, that is, the identity of the manufacturer (Clerke Technicorp) and the place of manufacture (Santa Monica, California), both of which were stamped on the revolver (the revolver had been admitted into evidence as exhibit #A-1), and the fact that the revolver had been seized in Missouri.” Id. at 315-16 (emphasis added).
Similarly, in Gresham the defendant was found guilty of possession of a firearm by a convicted felon. See 118 F.3d at 258. On appeal, defendant claimed that the district court abused its discretion by permitting the government to offer hearsay testimony in order to satisfy the jurisdictional nexus required by § 922(g)(1). The Fifth Circuit affirmed the conviction, stating, “[p]roof of the interstate nexus to the firearm may be based upon expert testimony by a law enforcement officer.” Id. at 266 (citing United States v. Privett, 68 F.3d 101, 104 (5th Cir.1995)). The court reasoned, “it is axiomatic that expert opinions may be based on facts or data of a type reasonably relied upon by experts in a particular field, even if the sources are not admissible evidence.” Id. (citing Fed.R.Evid. 703).
At trial, the prosecution offered the testimony of two ATF special agents. The agents testified that the component parts of the pipe bomb had been manufactured outside Texas and had traveled in interstate commerce.16 The agents, who were admitted as experts, based their testimony on studies of distinctive markings on the products, corporate literature and reference materials maintained by the ATF, discussions with the manufacturers, and their personal experience in law enforcement. See id. After reviewing these facts, the Fifth Circuit stated, “[w]e have regularly upheld such expert testimony against hearsay challenges, holding that expert testimony is admissible to satisfy the jurisdictional nexus required by § 922(g)(1).” Id.
The Gresham court cited three prior Fifth Circuit opinions, noting that the expert testimony had relied, in whole or part, on markings on the weapons in each of these cases. See Wallace, 889 F.2d at 584; *103Merritt, 882 F.2d at 920; Harper, 802 F.2d at 121. The court determined, “[i]n the instant case, the ATF experts relied on similar information.” Gresham, 118 F.3d at 266. Therefore, “the district court did not abuse its discretion in admitting the expert testimony to satisfy the jurisdictional nexus element.” Id. at 267.
Here, no distinctive markings were testified to regarding the firearm in question.
C. The Facts of This Case are Unique
The majority also fails to acknowledge that the facts of this case are absolutely unique. No other case has considered what evidence is appropriate to establish interstate nexus pursuant to Rule 703 where the firearms manufacturer has manufacturing facilities in the state of possession. Obviously, what constitutes reasonable rebanee in one context does not necessarily apply to an entirely different set of facts.
Under any approach, the “reasonably relied upon” standard necessarily requires focus on the specific facts and circumstances surrounding the case, the precise opinion offered, and the particulars of the basis for that opinion. As a consequence, it is not possible to identify bases for expert opinion that are always reasonably reliable. Thus, precedent on the questions raised by Rule 703 may be of dubious value.
29 Charles Alan Wright & Victor James Gold, Federal Practice and Procedure § 6274 (1997). For this reason as web, I believe that the majority’s less than critical treatment of the case law is less than satisfying.
D. Policy Considerations
Finally, as a matter of policy, the Court is setting a dangerous precedent by allowing a party to rely on its own hearsay compilation as a basis for expert opinion. In my mind, there is absolutely no justification for the Court’s reflexive deference to the ATF on the issues presented by this appeal. Accordingly, for the reasons stated, I would hold that Agent Cooney’s testimony is not based on facts or data reasonably relied on by experts in the field in formulating an opinion as to interstate nexus. See Fed.R.Evid. 703.
V. The Sixth Amendment
The failure of Agent Cooney’s testimony-to meet the requirements of Fed.R.Evid. 703 is sufficient for a finding of reversible error. However, my concern runs deeper than the improper adherence to the technical intricacies of the Federal Rules of Evidence. Specifically, this is a criminal case and the defendant enjoys the protection of the Sixth Amendment’s Confrontation Clause.
Where an expert relies on non-hearsay evidence, such as markings on the weapon, the evidence need only comply with Rule 703. However, where, as here, the testimony offered by the prosecution purports to rely on hearsay, the evidence must comply both with Rule 703 and the Confrontation Clause. The Seventh Circuit explained:
In criminal cases, a court’s inquiry under Rule 703 must go beyond finding that hearsay rebed on by an expert meets these standards. An expert’s testimony that was based entirely on hearsay reports, while it might satisfy Rule 703, would nevertheless violate a defendant’s constitutional right to confront adverse witnesses.
United States v. Lawson, 653 F.2d 299, 302 (7th Cir.1981).
The Confrontation Clause gives a criminal defendant the right “to be confronted with the witnesses against him.” U.S. Cont. art. VI. The central concern of the Confrontation Clause is “to ensure the reliability of the evidence against a criminal defendant by subjecting it to rigorous testing in the context of an adversary proceeding before the trier of fact.” Maryland v. Craig, 497 U.S. 836, 845, 110 S.Ct. 3157, 111 L.Ed.2d 666 (1990). Accordingly, pur*104suant to the Confrontation Clause, a defendant is “guaranteed an opportunity for effective cross-examination.” Delaware v. Van Arsdall, 475 U.S. 673, 678-679, 106 S.Ct. 1431, 89 L.Ed.2d 674 (1986).
The opportunity for cross-examination, protected by the Confrontation Clause, is critical for ensuring the integrity of the fact-finding process. Cross-examination is the principle means by which the believability of a witness and the truth of his testimony are tested.
Kentucky v. Stincer, 482 U.S. 730, 736, 107 S.Ct. 2658, 96 L.Ed.2d 631 (1987) (quoting Davis v. Alaska, 415 U.S. 308, 316, 94 S.Ct. 1105, 39 L.Ed.2d 347 (1974)). In light of a defendant’s right to cross-examination, out-of-court statements are admissible in a criminal trial only under limited circumstances.
Specifically, the Supreme Court has held that the Confrontation Clause is violated where an out-of-court statement of a witness does not bear adequate “indicia of reliability.” Ohio v. Roberts, 448 U.S. 56, 66, 100 S.Ct. 2531, 65 L.Ed.2d 597 (1980). The Supreme Court has stated that “indi-cia of reliability” can be demonstrated in two ways. Where the evidence falls within “a firmly rooted hearsay exception,” reliability can be inferred. Id. All other cases require “a showing of particularized guarantees of trustworthiness,” id., such that “adversarial testing would be expected to add little, if anything, to their reliability,” Lilly v. Virginia, 527 U.S. 116,-, 119 S.Ct. 1887, 1894, 144 L.Ed.2d 117 (1999). Further, the “particularized guarantees of trustworthiness” must be “drawn from the totality of circumstances that surround the making of the statement and that render the declarant particularly worthy of belief.” Idaho v. Wright, 497 U.S. 805, 820, 110 S.Ct. 3139, 111 L.Ed.2d 638 (1990).
Roberts and Wright are illustrative. In Roberts, the Supreme Court held that an out-of-court statement by an unavailable witness was sufficiently reliable to be admitted at trial, consistent with the Confrontation Clause, because defense counsel had engaged in full cross-examination of the witness at the preliminary hearing where the statement was made. See 448 U.S. at 70-73, 100 S.Ct. 2531. In contrast, in Wright the Supreme Court held that the hearsay statements of a child sexual abuse victim lacked the particularized guarantees of trustworthiness required for admission under the Confrontation Clause. See 497 U.S. at 826, 110 S.Ct. 3139. The Court focused on the “presumptive unreliability of out-of-court statements” and on the “suggestive manner” in which the child’s doctor conducted the interview. Id.
Here, even a cursory examination of the record shows that there are no “indicia of reliability” sufficient to uphold the admission of Agent Cooney’s testimony regarding the interstate nexus prong of § 922(g)(1). See Roberts, 448 U.S. at 66, 100 S.Ct. 2531. First, Agent Cooney offered the out-of-court statements of Smith & Wesson historian Roy Jinks as substantive evidence against the defendant. These statements were made in a telephonic interview that was conducted by the government without procedural safeguards after criminal proceedings had begun. Given the “totality of the circumstances,” there is no reason to believe that these out-of-court statements offered by the prosecution to prove interstate nexus are “particularly worthy of belief.” Wright, 497 U.S. at 820, 827, 110 S.Ct. 3139. Second, Agent Cooney relied on in-house ATF files. As I already indicated, there is little difference, from a hearsay standpoint, between the ATF’s internal reference materials, which are compiled by ATF agents interviewing firearm manufacturers in the field, and a telephone call to the manufacturer. These records have not been subjected to public scrutiny, and they are not likely to be available pursuant to the Freedom of Information Act. See 5 U.S.C. § 552(c)(7). Given the presumption of inadmissibility accorded accusatory hearsay statements not admitted pursuant to a firmly rooted hearsay exception, see id. (citing Lee v. Illinois, 476 U.S. 530, 543, 106 S.Ct. 2056, 90 L.Ed.2d 514 (1986)), the government’s evidence of interstate nexus does not possess “particularized guaran*105tees of trustworthiness” sufficient to uphold appellant’s conviction.
The Smith & Wesson employees, in being saved an appearance before the jury, were rendered immune from cross-examination. The prosecution was thereby allowed to establish a jurisdictional fact by simply producing a witness who did nothing but summarize out-of-court statements made by others. Consequently, the defendant had no way to test the veracity of the evidence offered against him. This use of hearsay evidence, in addition to failing the requirements of Fed.R.Evid. 703, denied appellant his constitutional right to confront adverse witnesses. See Lawson, 653 F.2d at 302.
In a criminal case a court’s inquiry under Rule 703 must go beyond a finding that the hearsay relied on by an expert meets the standards of the Federal Rules of Evidence. If this Court is willing to allow a government agency to rely on its own internal manuals and post-indictment telephone calls to establish a basic element of a crime, simply by clothing the testifying agent with the unwarranted aura of “expert,” then, in my opinion, the plain language of the Confrontation Clause has been emasculated beyond recognition. Requiring the government to produce non-hearsay evidence on the jurisdictional requirement of § 922(g)(1) is hardly a major burden on the prosecution. Particularly where, as here, the weapon in question is stamped with a serial number, it is a minor bureaucratic inconvenience to establish where the weapon was manufactured, by requiring the subpoenaing of records from the manufacturer. The resources of the government can hardly be strained by requiring such direct proof of interstate nexus.
CONCLUSION
For the reasons stated above, I respectively dissent.
. See U.S. Const, art. VI ("In all criminal prosecutions, the accused shall enjoy the right ... to. be confronted with the witnesses against him....").
. Although this circuit has no similar precedent, the idea that certain evidentiary issues warrant a stricter standard of review is not novel. See, e.g., Olsen v. Coneiro, 189 F.3d 52, 58 (1st Cir.1999) ("Here the evidentiary questions are primarily questions of law about the interpretation of the Federal Rules of Evidence, which we review de novo.”); United States v. Sposito, 106 F.3d 1042, 1046 (1st Cir.1997) (same).
. See, e.g., Davis v. American Jet Leasing, 864 F.2d 612, 615 (8th Cir. 1988).
. See, e.g., United States v. Systems Architects, 757 F.2d 373, 377 (1st Cir.1985).
. See, e.g., First Nat’l State Bank v. Reliance Elec. Co., 668 F.2d 725, 731 (3d Cir. 1981).
. See, e.g., Bauman v. Centex Corp., 611 F.2d 1115, 1120-21 (5th Cir. 1980).
. See, e.g., Federal Crop Ins. Corp. v. Hester, 765 F.2d 723, 728 (8th Cir.1985).
. See, e.g., Wilder Enters. v. Allied Artists Pictures, 632 F.2d 1135, 1143 (4th Cir. 1980).
. See, e.g., Shad v. Dean Witter Reynolds, 799 F.2d 525, 527-30 (9th Cir.1986).
. See, e.g., United States v. Echeverri, 982 F.2d 675, 680 (1st Cir. 1993); United States v. Castiello, 915 F.2d 1, 3 (1st Cir.1990).
. Although the distinction between the location of a manufacturer’s facilities and the "actual place of manufacturer” is normally incidental, it is the critical issue in a case, such as this one, where the manufacturer has facilities both in the state of possession and outside of it.
. See also Ruiz-Troche v. Pepsi Cola of Puerto Rico Bottling Co., 161 F.3d 77, 81 (1st Cir. 1998) ("To be admissible, expert testimony must be relevant not only in the sense that all evidence must be relevant, see Fed.R.Evid. 402, but also in the incremental sense that the expert’s proposed opinion, if admitted, *98likely would assist the trier of fact to understand or determine a fact in issue.”); Ed Peters Jewelry Co. v. C & J Jewelry Co., 124 F.3d 252, 259 (1st Cir.1997) (holding trial court "must perform its gatekeeping function, by assessing whether the testimony 'will assist the trier of fact to understand the evidence or to determine a fact in issue' " (quoting Fed.R.Evid. 702)); United States v. Montas, 41 F.3d 775, 784 (1st Cir.1994) ("Expert testimony on a subject that is well within the bounds of a jury’s ordinary experience generally has little probative value.”); United States v. Rohm, 993 F.2d 1405, 1413 (9th Cir.1993) ("Our [Rule 702] inquiry has generally focused upon whether the expert testimony improperly addresses matters within the understanding of the average juror.... [T]his circuit continues to guard — perhaps too jealously — from expert elucidation, areas believed to be within the jurors’ common understanding.”); United States v. Sepúlveda, 15 F.3d 1161, 1183 (1st Cir.1993) ("[T]he trial judge performs a gatekeeping function, determining whether it is reasonably likely that the expert possesses specialized knowledge which will assist the trier better to understand a fact in issue.”); United States v. Cruz, 981 F.2d 659, 664 (2d Cir. 1992) (holding expert testimony is not admissible unless subject matter has "esoteric aspects reasonably perceived as beyond the ken of the jury”); United States v. Lamattina, 889 F.2d 1191, 1194 (1st Cir.1989) (expert testimony is inad-missable where jury is able to determine issues "to the best possible degree”); Andrews v. Metro North Commuter R. Co., 882 F.2d 705, 708 (2d Cir.1989) ("For an expert’s testimony to be admissible under [Rule 702] it must be directed to matters within the witness' scientific, technical, or specialized knowledge and not to lay matters which a jury is capable of understanding and deciding without the expert's help.”); United States v. Lundy, 809 F.2d 392, 395 (7th Cir. 1987) ("Courts agree that dt is improper to permit an expert to testify regarding facts that people of common understanding can easily comprehend.” (citing cases)); Scott v. Sears, Roebuck & Co., 789 F.2d 1052, 1055 (4th Cir. 1986) ("Rule 702 makes inadmissible expert testimony as to a matter which obviously is within the common knowledge of jurors because such testimony, almost by definition, can be of no assistance.”); 1 John W. Strong et al., McCormick On Evidence § 13 (1999) ("To warrant the use of expert testimony, the proponent must establish at least two general elements. First, traditionally the subject of the inference must be so distinctively related to a science, profession, business, or occupation as to be beyond the ken of lay persons.... Second, the witness must have sufficient skill or knowledge related to the pertinent field or calling that his inference will probably aid the trier in the search for truth.”); 29 Charles Alan Wright & Victor James Gold, Federal Practice and Procedure § 6274 (1997) ("The most important factor in determining whether expert testimony will 'assist [the trier of fact]' is the jury's need for expert testimony to accurately determine the facts. Thus, expert testimony assists where it relates to esoteric matters beyond the experience of most lay people. Similarly, experts are needed where the testimony concerns complex matters that challenge the comprehension of lay people. Expert testimony may also be helpful where the subject is simply confusing.... On the other hand, expert testimony does not assist where the jury has no need @for an opinion because it easily can be derived from common sense, common experience, the jury’s own perceptions, or simple logic. For the same reason, expert testimony may not be helpful where there are other means to put the jury in a position to accurately decide the facts.”).
. The majority takes issue with my Rule 702 analysis, stating that a trial court need not deconstruct an expert’s testimony into discrete components. See supra note 5. The indication is that opinion testimony on interstate nexus may be proper even if expert testimony on the place of manufacture is not. I respectfully fail to see how this can be. First, it is settled law that a trial court must perform a gatekeeping function to ensure that proposed expert testimony complies with the *99Federal Rules of Evidence. See, e.g., Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 591-93, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993); McDonald v. Fed. Lab., Inc., 724 F.2d 243, 248 (1st Cir.1984). Second, I am not aware of a single case that states an expert once anointed as such may testify to subjects that do not meet the requirements of Rule 702. Third, and most important, the interstate nexus of a firearm generally requires knowledge of two things: (1) the place of manufacture, and (2) the state of possession. If, as I have argued, neither the place of manufacture nor the state of possession constitutes specialized knowledge, and therefore is not proper Rule 702 testimony, then I fail to see how testimony on the ultimate issue of fact, interstate nexus, fairs better.
. See, e.g., In re Paoli R.R. Yard PCB Litig., 35 F.3d 717, 748 (3d Cir.1994) ("It is the judge who makes the determination of reasonable reliance, and ... for the judge to make the factual determination under Rule 104(a) that an expert is basing his or her opinion on a type of data reasonably relied upon by experts, the judge must conduct an independent evaluation into reasonableness.”); United States v. Locascio, 6 F.3d 924, 938 (2d Cir.1993) (“We agree that a district court is not bound to accept expert testimony based on questionable data simply because other experts use such data in the field.”); University of Rhode Island v. A.W. Chesterton Co., 2 F.3d 1200, 1218 (1st Cir.1993) ("Rules 703 and 705 do not afford automatic entitlements to proponents of expert testimony. Rule 703 requires the trial court to give 'careful consideration’ to any inadmissible facts upon which the expert will rely, in order to determine whether reliance is 'reasonable.' ”); Slaughter v. Southern Talc Co., 919 F.2d 304, 306-07 (5th Cir.1990) ("Federal Rule of Evidence 703 requires courts to examine the reliability of an expert's sources to determine whether they satisfy the threshold established by the rule.”); Head v. Lithonia Corp., 881 F.2d 941, 944 (10th Cir.1989) ("Implicit in [Rule 703] is the court’s [obligation] to make a preliminary determination pursuant to Rule 104(a) whether the particular underlying data is of a kind that is reasonably relied upon by experts in the particular field in reaching conclusions.... Thus, the district court may not abdicate its independent responsibilities to decide if the bases meet minimum standards of reliability as a condition of admissibility.” (internal quotes omitted)); Almonte v. National Union Fire Ins. Co., 787 F.2d 763, 770 (1st Cir.1986) (trial court erred in failing to conduct more extensive investigation into whether police expert’s reliance on facts or data was reasonable); Soden v. Freightliner Corp., 714 F.2d 498, 505 (5th Cir.1983) ("Though courts have afforded experts a wide latitude in picking and choosing the sources on which to base opinions, Rule 703 nonetheless requires courts to examine the reliability of those sources.”); Baumholser v. Amax Coal Co., 630 F.2d 550, 553 (7th Cir.1980) ("It is for the trial court to determine, in the exercise of its discretion, whether the expert's sources of information are sufficiently reliable to warrant reception of the opinion.”).
. I disagree with the majority’s reading of the record on this point. See supra note 9. On direct examination, Agent Cooney was asked to provide "a brief description of Exhibit 7 [the Corey shotgun], including the weapon type, markings, and its history.” Agent Coo-ney replied:
Exhibit 7 is a Smith & Wesson, Model 916-A, 12-gauge, pump-action shotgun, serial number 7B1279. Exhibit 7 was manufactured by the Smith & Wesson firearms company of Springfield, Massachusetts. It is, by design, a pump-action shotgun. My examination revealed that it has a barrel length of approximately 30 and )6 inches, and an overall length of approximately 50 and % inches.
(Emphasis added). As I read this passage, the only marking identified by Agent Cooney was the serial number. Moreover, although this passage identifies the manufacturer of the shotgun, nothing here identifies the place of manufacture. (Smith & Wesson is headquartered in Springfield, Massachusetts, but the company has manufacturing facilities in Maine, Ohio, and Massachusetts.) More important, however. Agent Cooney was subsequently asked numerous times on what basis he formulated his opinion on interstate nexus. He testified that he relied on a telephone call to Smith & Wesson, ATF research materials, and his personal experience. He did not indicate any reliance on markings on the shotgun. Accordingly, I respectfully suggest that there is nothing in the record that fairly indicates that Agent Cooney relied on distinctive markings on the firearm in formulating his opinion on interstate nexus.
. The court determined that the component parts of a “pipe bomb” constituted "firearms” for purposes of § 922(g)(1). See 118 F.3d at 265.