concurring in part, dissenting in part, and concurring in the judgment reversing the convictions and remanding for a new trial.
I concur in the portions of the opinion styled “The Plastic Bag.” Accordingly, I would reverse the convictions. I would also reverse the convictions for the conduct described in the portion of the opinion styled “The Sheriffs Conduct.” I do not join in the portions of the opinion styled “Fingernail Comparison Evidence,” “The Sufficiency of the Fingernail Comparison,” “Should the Expert’s Testimony Have Been Struck,” and “Presentation of the Expert’s Paper to the Jury.” For the reasons that follow, I would reverse the trial judge’s decision on all the issues relating to the expert witness.
In contesting the admissibility of the “scientific” evidence, Cotton did not urge in the trial court or in this Court that the Frye test be employed. Citing Spencer v. Commonwealth, 238 Va. 275, 290, 384 S.E.2d 775, 783 (1989), cert. denied, 493 U.S. 1036 (1990), and O’Dell v. Commonwealth, 234 Va. 672, 695-96, 364 S.E.2d 491, 504, cert. denied, 488 U.S. 871 (1988), Cotton acknowledged that the Supreme Court of Virginia rejected the Frye test. He argued instead that the Commonwealth failed to establish either that the evidence met the standard of being “a reliable scientific technique” or that “the tests performed . . . were properly conducted,” both of which are required by Spencer. See 238 Va. at 290, 384 S.E.2d at 783. I agree with Cotton’s analysis.
*317Upon nothing more than a self-described expert’s testimony that her proposed testimony was scientifically valid and reliable, the trial judge accepted her thesis that (1) each human being’s fingernails possess characteristics unique to that human being, and (2) the technique for measuring that uniqueness was reliable. The record in this case failed to establish either of those theses.
The purported fingernail comparison expert, Ann Davis Jones, is employed by the Commonwealth of Virginia’s Division of Forensic Science as a forensic scientist in the field of firearms and tool mark identification. Her curriculum vitae indicates she was first employed in the forensic laboratory in 1984 as an analytical chemist to perform drug analyses. Jones testified that her current expertise was in the field of tool marks. She did not perform fingerprint identifications as a part of her job in the forensic laboratory. She also admitted that “[tjhere are studies of bite marks and things like that, but I don’t examine those.” In addition, Jones testified that this case was the first in which she testified concerning fingernail comparisons.
Jones has never taken any classes in which she studied fingernail identifications. She also testified that she has never prepared a paper for publication on the subject matter. Nothing on her vitae indicates formal study, training, or professional experience in the area of fingernail identification.
Jones’s curriculum vitae indicates that she participated in a Fingernail Striae Symposium at the 22nd Annual AFTE Training Seminar and presented a talk based on a paper she prepared titled “The Evidentiary Value of Fingernail Ridge Patterns as a Means of Personal Identification.” The record indicates that Jones prepared the paper in 1990 during “independent study/research” at Virginia Commonwealth University. The paper contains three pages of text and consists of the following: (1) six paragraphs of introduction that generally discuss research done by other people and the problems encountered in getting courts to accept the technique; (2) two paragraphs titled “Materials and Methods” that describe her comparisons of fingernail clippings from five individuals; (3) two paragraphs titled “Results and Discussion” in which she describes the examinations and conclusions; and (4) a one paragraph summary in which she concludes that the ridge patterns on the five individuals “have been found to be unique.” Also attached to the paper are a list of eighteen references and an ap*318pendix summarizing studies and court decisions.
Jones testified that she did personal research involving seven pairs of identical twins who were “part of the Medical College of Virginia identical twins study.” She further testified that she “found no matches on any of the fingernails on any of the sets of identical twins.” She also said that she studied the fingernail of a colleague who broke a fingernail and discovered that she could match the striation patterns from the broken nail to the new fingernail that grew.
She testified that she “probably . . . studied approximately thirty individuals” since 1984. She further testified that she was “not aware of any studies [involving] more than thirty-seven people.” She said that there have been “twenty-three to twenty-five” written studies on cases and that the reference page to her paper includes a list of publications of almost all the studies that have been done. She also testified that toenail comparisons were first admitted as evidence in court in 1955 in a fraud case in Nigeria.
Jones testified that other persons had studied dermal ridges under fingernails and concluded that the “ridges on the upper surface of the nail bed are . . . unique.” She also testified that she was aware that experts have testified that insufficient work was done in the field to establish that fingernails are unique. Furthermore, Jones testified that she was aware of the practice in fingerprint identification of requiring a certain number of points of identification in order to make a positive identification. Her methodology in fingernail identification, however, can be established on only one point of identification. She gave no indication that her methodology has minimum standards of certainty.
Notwithstanding Jones’s testimony that her professional qualifications were in the field of firearms and tool mark identification, she was offered as an expert in the field of the physiology of fingernail comparisons. It is well established in Virginia, however, that a witness who is an expert in one field is not ipso facto an expert in another field. VEPCO v. Lado, 220 Va. 997, 1005, 266 S.E.2d 431, 436 (1980). That principle applies to bar the witness’s testimony “even though that [other] field is closely related” to the witness’s area of expertise. Tazewell Oil Co. v. United Va. Bank, 243 Va. 94, 110, 413 S.E.2d 611, 620 (1992). Furthermore, it is equally well established that “the expressed belief of a witness *319that [s]he is an expert does not ipso facto require [her] qualification.” Noll v. Rahal, 219 Va. 795, 800, 250 S.E.2d 741, 744 (1979). Jones’s expertise was based solely upon her reading of other researchers’ works and her personal comparison of the fingernails from five individuals. Her interest and enthusiasm in the subject, more akin to the kind of interest and enthusiasm one might have in a hobby, does not turn that passion into “a reliable scientific technique” merely because she said the technique is reliable.
The fields of forensic odontology and “tool marks” have a scientifically recognized basis for identification. See Commonwealth v. Graves, 456 A.2d 561, 566-67 (Pa. Super. Ct. 1983). The question whether given a certain fingernail, its owner can be identified to the exclusion of all other people, however, is a matter not encompassed within those disciplines. Id. at 567-68. “Tool marks” has long been recognized as a reliable scientific basis for making comparisons of the wound impression that a fingernail leaves in another object. Id. at 566. That kind of identification analysis must be distinguished, however, from “an attempt to identify an individual based on some of his personal characteristics.” Id. at 567.
Although the court in People v. Wesley, 303 N.W.2d 194 (Mich. Ct. App. 1981), aff'd, 365 N.W.2d 692 (Mich. 1984), applied the Frye test to rule that fingernail comparison testimony was inadmissible, the opinion is germane to this case because the court addressed generally the scientific validity of fingernail comparisons. Significantly, the court likened the reliability of such evidence to that of polygraphs and held that the analysis did not provide sufficient evidence of reliability of the technique. Id. at 196. Virginia courts also have held that not all fields considered scientific are deemed to be based upon reliable scientific technique. See Lee v. Commonwealth, 200 Va. 233, 237, 105 S.E.2d 152, 155 (1958) (polygraphs, which are called “lie detector tests,” are not scientifically reliable); Hall v. Commonwealth, 12 Va. App. 198, 208-10, 403 S.E.2d 362, 368-69 (1991) (hypnotically refreshed testimony is not the result of a reliable scientific technique).
In State v. Shaw, 369 N.W.2d 772 (Wis. Ct. App.), appeal denied, 375 N.W.2d 214 (Wis. 1985), the Wisconsin court rejected the Frye test and admitted testimony concerning “the theory that human fingernails possess distinct and unique longitudi*320nal striations.” Id. at 773. In so doing, however, the court held that Wisconsin law “imposes no threshold of reliability other than that implicit in a determination of relevancy and qualification of the expert.” Id. at 774. The standard used in Shaw is significantly less exacting than the standard articulated in Spencer.
In a recent case, the United States Supreme Court ruled “that the Frye test was superseded by the adoption of the Federal Rules of Evidence.” Daubert v. Merrell Dow Pharmaceuticals, _ U.S__, _, 113 S. Ct. 2786, 2793 (1993) (footnote omitted). In discussing factors to be considered in determining scientific reliability, a threshold finding that must be made under the Rules, the Court made the following observations:
Ordinarily, a key question to be answered in determining whether a theory or technique is scientific knowledge that will assist the trier of fact will be whether it can be (and has been) tested. “Scientific methodology today is based on generating hypotheses and testing them to see if they can be falsified; indeed, this methodology is what distinguishes science from other fields of human inquiry.” Green, [Expert Witnesses and Sufficiency of Evidence in Toxic Substance Litigation: The Legacy of Agent Orange and Bendectin Litigation, 86 Nw. U. L. Rev. 643] at 645 [1992]. See also C. Hempel, Philosophy of Natural Science 49 (1966) (“[T]he statements constituting a scientific explanation must be capable of empirical test”); K. Popper, Conjectures and Refutations: The Growth of Scientific Knowledge 37 (5th ed. 1989) (“[T]he criterion of the scientific status of a theory is its falsifiability, or refutability, or testability”).
Another pertinent consideration is whether the theory or technique has been subjected to peer review and publication. Publication (which is but one element of peer review) is not a sine qua non of admissibility; it does not necessarily correlate with reliability, see S. Jasanoff, The Fifth Branch: Science Advisors as Policymakers 61-76 (1990), and in some instances well-grounded but innovative theories will not have been published, see Horrobin, The Philosophical Basis of Peer Review and the Suppression of Innovation, 263 J. Am. Med. Assn. 1438 (1990). Some propositions, moreover, are too particular, too new, or of too limited interest to be pub*321lished. But submission to the scrutiny of the scientific community is a component of “good science,” in part because it increases the likelihood that substantive flaws in methodology will be detected. See J. Ziman, Reliable Knowledge: An Exploration of the Grounds for Belief in Science 130-133 (1978); Reiman and Angelí, How Good is Peer Review?, 321 New Eng. J. Med. 827 (1989). The fact of publication (or lack thereof) in a peer-reviewed journal thus will be a relevant, though not dispositive, consideration in assessing the scientific validity of a particular technique or methodology on which an opinion is premised.
Additionally, in the case of a particular scientific technique, the court ordinarily should consider the known or potential rate of error, see, e.g., United States v. Smith, 869 F.2d 348, 353-354 (CA7 1989)(surveying studies of the error rate of spectrographic voice identification technique), and the existence and maintenance of standards controlling the technique’s operation. See United States v. Williams, 583 F.2d 1194, 1198 (CA2 1978)(noting professional organization’s standard governing spectrographic analysis), cert. denied, 439 U.S. 1117 (1979).
Finally, “general acceptance” can yet have a bearing on the inquiry. A “reliability assessment does not require, although it does permit, explicit identification of a relevant scientific community and an express determination of a particular degree of acceptance within that community.” United States v. Downing, 753 F.2d at 1238. See also, 3 Weinstein & Berger 1Í702[03], pp. 702-41 to 702-42. Widespread acceptance can be an important factor in ruling particular evidence admissible, and “a known technique that has been able to attract only minimal support within the community,” Downing, supra, at 1238, may properly be viewed with skepticism.
Dow, 113 S. Ct. at 2796-97.
Although consideration of these factors is not expressly required by any ruling from the Supreme Court of Virginia, these factors manifest a concern not limited to federal jurisprudence, that the principles and methodology which underlie a proffered technique be based upon “a reliable scientific technique,” the test espoused *322by Spencer. 238 Va. at 289, 384 S.E.2d at 782. Furthermore, these factors are relevant in Virginia because our Supreme Court requires an inquiry into the question of reliability.
When scientific evidence is offered, the court must make a threshold finding of fact with respect to the reliability of the scientific method offered, unless it is of a kind so familiar and accepted as to require no foundation to establish the fundamental reliability of the system, such as fingerprint analysis; or unless it is so unreliable that the considerations requiring its exclusion have ripened into rules of law, such as “lie-detector” tests; or unless its admission is regulated by statute, such as blood-alcohol test results.
Spencer v. Commonwealth, 240 Va. 78, 97, 393 S.E.2d 609, 621, cert. denied, 498 U.S. 908 (1990) (citations omitted).
The record in this case reflects no inquiry or findings which satisfy that concern. Based upon the evidence in this record, I would hold that the trial judge erred in admitting Jones’s testimony as expert opinion evidence. Jones’s testimony simply failed to meet the two-prong test articulated in Spencer. Thus, I would hold that the trial judge erred in allowing Jones to testify that the fingernail found in the cash register after the robbery was from Cotton’s finger “to the exclusion of all the other people in the world.” Her further testimony that there was no minimum number of points of comparison that must be made to establish identity of fingernails simply lacks support.
The Commonwealth also failed to establish that Jones’s fingernail ridge identification “tests . . . were properly conducted.” Spencer, 238 Va. at 290, 384 S.E.2d at 783. Indeed, when defense counsel sought to explore that issue, the trial judge erroneously limited defense counsel’s cross-examination of Jones.
At trial, the Commonwealth proved on its direct examination that Jones had appeared at two meetings where she “gave a talk” concerning fingernail identifications. Defense counsel sought to examine Jones using the paper that Jones had prepared and used as the basis for the “talk” she gave at the two meetings. That inquiry was relevant because the paper contained a caution concerning the comparison samples to be used. Defense counsel did not offer the paper as evidence. The trial judge refused to allow defense counsel *323to examine Jones concerning the variance between the technique she employed in this case and the testing method described in her own writings. That ruling was error. See Griffett v. Ryan, 247 Va. 465, 473-74, 443 S.E.2d 149, 154 (1994); Hopkins v. Gromovsky, 198 Va. 389, 395, 94 S.E.2d 190, 194 (1956). The scope of the cross-examination was relevant to issues raised on direct examination and sought to expose errors in the conduct of the test.
For these additional reasons, I would also hold that the trial judge erred on the issues concerning the expert witness. The record fails to establish that Jones was qualified to testify as an expert on the uniqueness of human fingernails.