On the basis of testimony given by appellee Leonard Johnson in a personal injury action, the Commonwealth of Pennsylvania, appellant herein, charged appellee with two counts of perjury, 18 Pa.C.S. § 4902, two counts of false swearing in official matters, 18 Pa.C.S. § 4903(a), and one count of tampering with or fabricating physical evidence, 18 Pa.C.S. § 4910. In response to a motion in limine filed by appellee, the trial court barred the Commonwealth from introducing into evidence expert testimony that, based on the results of ink analysis, two pages of handwritten notes referred to by appellee during the trial could not have been written in 1979, as appellee testified they were. In this appeal, the Commonwealth contends that the trial court abused its disсretion in granting the motion in limine. For *268 the reasons set forth below, we reverse the order of the trial court and remand for further proceedings.
This case had its origin in the 1985 civil trial of Bolton v. Southeastern Pennsylvania Transportation Authority, No. 4895 July Term 1981, an action brought by Yvonne Bolton to recover damages for injuries allegedly suffered as the result of a 1979 accident involving a trolley operated by the Southeastern Pеnnsylvania Transportation Authority (SEPTA). During discovery, SEPTA issued a subpoena for all of the medical records maintained on Ms. Bolton by appellee, her treating physician.
At trial appellee referred to several pages of notes that he had allegedly written after Ms. Bolton’s visits to his office in 1979. The notes indicated that in her early visits Ms. Bolton had complained of lowеr back pain. According to the Commonwealth, these notes had not been included in the records supplied by appellee in response to SEPTA’s subpoena, and the office report included in the records supplied to SEPTA made no reference to complaints of lower back pain during Ms. Bolton’s early visits to appellee.
Later in the trial, SEPTA called as a witness Albert Lyter, a forensic consultant whose specialty was document analysis. Mr. Lyter testified that two of the pages of handwritten notes could not have been written before January 1984. This could be determined, he explained, because Formulabs, the manufacturer of the ink with which the notes were written, had added a different chemical “tag” to its ink every year since 1979, and the ink on the pages in question contained the tag that had been added to ink manufactured in 1984.
As the result of Albert Lyter’s testimony, the Commonwealth charged appellee with perjury, false swearing in official matters, and tampering with or fabricating physical evidence. At the preliminary hearing, the Commonwealth offered the testimony of Mr. Lyter and of counsel for SEPTA in the Bolton case. After considering the evidence offered at the preliminary hearing, the trial court dismissed the charges against appellee. Appellee was later re-arrest *269 ed on the same charges, and the Commonwealth notified the defense of its intention to present expert testimony concerning the ink used by appellee to write the notes.
Apрellee then filed an omnibus pretrial motion, which included a motion in limine asking the court to rule that the Commonwealth’s expert testimony was inadmissible. At a hearing on the motion, the Commonwealth offered the testimony of two experts, Richard Brunelle and Dr. Antonio Cantu, concerning the reliability and acceptance in the scientific community of ink analysis as a method of dating ink. On May 18, 1989, the trial court entered an order, accompanied by findings of fact and conclusions of law, granting appellee’s motion in limine. The Commonwealth’s subsequent motion for reconsideration was denied, and this timely appeal followed.
The Commonwealth has certified, pursuant to
Commonwealth v. Dugger,
A motion
in limine
is a procedure for obtaining a ruling on the admissibility of evidence prior to or during trial, but before the evidence has been offered. L. Packel & A.B. Poulin,
Pennsylvania Evidence
§ 103.3 (1987). This Court has reviewed rulings on motions
in limine
by applying the scope of review appropriate to the particular evidentiary matter at issue.
Commonwealth v. Laskaris,
expert opinion testimony is proper only where formation of an opinion on a subject requires knowledge, information, or skill bеyond what is possessed by the ordinary *270 juror. As stated in Commonwealth v. Leslie,424 Pa. 331 , 334,227 A.2d 900 , 903 (1967) (quoting Commonwealth v. Nasuti,385 Pa. 436 , 443,123 A.2d 435 , 438 (1956)), “ ‘Expert testimony is admissible in all cases, civil and criminal alike, when it involves explanations and inferences not within the range of ordinary training, knowledge, intelligence and experience.’ ”
Commonwealth v. Seese,
Appellee argued to the trial court, and argues on appeal, that 1) ink analysis does not meet the legal standard of admissibility in Pennsylvania, and 2) owing to the “two-witness rule,” perjury cannot be proved by opinion testimony. The majority of the trial court’s thirty-four findings of fact dealt with the experts’ qualifications and their testimony concerning ink analysis, and thе court expressed concern that “the process required to prove the falsity of Dr. Johnson’s notes lies in the hands of only a select group of individuals throughout this country, most of whom were trained by or who follow the procedures outlined by Mr. Brunelle” (Trial Court Opinion at 11-12). However, the court decided the motion on the basis of the second issue rather than the first and did not deсide whether ink analysis meets the legal standard of admissibility in Pennsylvania.
The trial court’s ruling presents a procedural problem that must be addressed. In its initial brief on appeal, the Commonwealth—understandably, in light of the trial court’s failure to rule on the ink analysis issue—challenged only the trial court’s interpretation and application of the “two-witness rule.” In his brief on appeal, appellee not only supported the trial court’s ruling on that issue but also argued that ink dating is not a recognized area of expertise in Pennsylvania. The Commonwealth then addressed the ink analysis issue in a reply brief, which was followed by a *271 reply brief for appellee. However, despite the extensive discussion of the ink analysis issue by the parties, we, as a reviewing court, decline to assume the role of factfinder by making an initial ruling on the issue. Accordingly, the admissibility of ink analysis is a matter that remains to be decided by the trial court, if and when the issue is raised on remand.
With this understanding, we turn to the trial court’s opinion. Section 4902(f) of the perjury statute, 18 Pa.C.S. § 4902(f), states that
“[i]n any prosecution under this section, except under subsection (e) of this section [perjury based on inconsistent statements under oath], falsity of a statement may not be established by the uncorroborated testimony of a single witness.”
According to the trial court,
the “corroboration” section of the statute is the codification of case law’s “two witness rule”, which protects a defendant by requiring that there be testimony of at least two witnesses to prove the falsity of the matter on whiсh the perjury is assigned, or one witness and corroboration. Commonwealth v. Russo,388 Pa. 462 , 464,131 A.2d 83 , 86 (1957). The “two witness rule” was later refined in Commonwealth v. Hude,492 Pa. 600 ,425 A.2d 313 , 322 [ (1981) ], in that corroboration [“]may be accomplished by the direct testimony of two witnesses or by direct testimony of one witness plus corroborating evidence.”
Trial Court Opinion at 13. Because expert testimony is opinion only, not proof of a fact, the court held, it does not substitute for direct or factual testimony and therefore cannot satisfy the corroboration requirement of § 4902(f). 1
*272 In response, the Commonwealth contends that the “two-witness rule” is not applicable where, as here, the evidence consists of proof in the form of documents. In any event, the Commonwealth argues, the rule prescribes only the necessary quantity, not the quality, of evidence. Thus, it does nоt prohibit the use of opinion evidence in a perjury prosecution.
As this Court explained in
Commonwealth v. Broughton,
In Broughton this Court was required to decide whether circumstantial evidence could be sufficient to support a conviction for perjury under the present statute, 18 Pa.C.S. § 4902. Acknowledging that if the rule of Field continued to be applicable, appellant’s conviction could not stand, the Court concluded that the adoption of 18 Pa.C.S. § 4902(f) had changed the two-witness rule.
We read this provision to mean that a witness may testify as to his direct observation, or he may provide circumstantial evidence; but in either case, he must be corroborated by thе testimony of another witness, whose testimony may provide either direct or circumstantial evidence.
*273
Id.
Appellee contends, in effect, that this Court’s opinion in
Broughton
was overruled
sub silentio
by the Supreme Court in
Commonwealth v. Hude,
In
Hude,
as appellee contends, the Supreme Court interpreted § 4902(f) tо require the direct testimony of two witnesses or the direct testimony of one witness plus corroborating evidence. In doing so, the Court cited
Broughton,
which interpreted the present statute, as well as
Field,
which interpreted the previous statute.
Id.,
The Commonwealth contends that not only does § 4902(f) not preclude a perjury conviction based solely on circumstantial evidence, but, pursuant to
Commonwealth v. Robinson,
This subsection ... does not purport to establish affirmatively the type or quality of the evidence necessary to convict. It seeks merely to prevent a conviction in a situation where oath has been pitted against oath. Thus, it establishes that a conviction for perjury cannot rest upon the “uncorroborated testimony of a single witness.” The rule has value in safeguarding witnesses in official proceedings from harassment by disappointed litigants. It also protects them from their own or another’s good-faith mistakes.
The provisions of 18 Pa.C.S. § 4902(e)[ 2 ], it has been held, do not prevent a conviction based on circumstantial evidence. Commonwealth v. Broughton,257 Pa.Super. 369 ,390 A.2d 1282 (1978) (rehearing denied). Similarly, the language of the subsection does not preclude a convic *275 tion where the only proof of falsity is documentary evidence. Thus, an uncorroborated record of a criminal conviction is sufficient to demonstrate the falsity of a sworn statement that the speaker has never been convicted of a crime. The documentary evidence, however, must be clear and positive.
Id.
The evidence at issue in thе present case is the testimony of expert witnesses concerning certain documents, namely, the handwritten notes of appellee. Appellee contends that this Court’s holding in
Robinson
does not permit a perjury conviction to be based on such evidence, since
Robinson,
unlike the case before us, “involved the production of business records, admissible as an exception to the hearsay rule, which are authenticated by the necessary witnesses and which contained direct facts of the occurrence or non-occurrence of certain events” (Brief for Appellee at 13). The holding in
Robinson
was not based upon the fact that the documents in question were admissible pursuant to the business records exception to the hearsay rule, however, but upon the fact that the evidence “was far more substantial than the uncorroborated testimony of a single witness” and “was positive and convincing.”
3
Id.,
332 Pa.Superior Ct. at 153,
Accordingly, as 18 Pa.C.S. § 4902(f) “does not purport to establish affirmatively the type or quality of the evidence necessary to convict” a defendant of perjury, it does not preclude the possibility that the Commonwealth will be able *276 to prove beyond a reasonable doubt, based upon the evidence available in the present case, that appellee committed perjury as defined in 18 Pa.C.S. § 4902(a). The Commonwealth asserts that its evidence will not consist solely of the experts’ testimony, but will also include evidence that when appellee was asked to supply all medical records relating to Yvonne Bolton, the only items not supplied were the handwritten notes in question. In addition, the Commonwealth points out, it may be able to discredit appellee's own testimоny through impeachment.
Whether the evidence eventually offered by the Commonwealth will prove beyond a reasonable doubt that appellee committed perjury is not a question that can or should be decided by this Court in an appeal from a pretrial ruling. At this juncture we are not required to weigh the evidence, but only to determine whether § 4902(f) precludes its admission. For this reason, it is unnecessary for us to address appellee’s claims that expert opinion testimony is the lowest grade of testimony and is evidence only of the expert’s opinion, not of facts. These claims concern the weight to be given to the evidence, not its initial admissibility.
In addition, we have reviewed the numerous cases involving challenges to wills that have bеen cited by appellee in an effort to show that “expert testimony cannot be received as independent evidence to impeach the validity of a document” (Brief for Appellee at 8). Assuming for the sake of argument that these civil cases are relevant to the criminal matter before us, we note that in
In re Estate of Cline,
the testimony of handwriting experts that a will offered for probate is a forgery corroborated by probative facts and circumstances may be sufficient to overcome the testimоny of those claiming to be subscribing witnesses to the questioned document and to support a finding of forgery and the corroborative evidence may be the most *277 nearly positive and direct evidence which the nature of the case will admit.
Id.,
In conclusion, it cannot be said that as a matter of law the expert opinion testimony which the Commonwealth proposes to offer will necessarily fail to satisfy the requirement of 18 Pa.C.S. § 4902(f) as interpreted by this Court in Commonwealth v. Robinson, supra. That being the case, the trial court’s decision to grant appellee’s motion in limine was a clear abuse of discretion, requiring us to reverse the court’s order оf May 18, 1989, and to remand the case for further proceedings.
Order reversed; case remanded for further proceedings; jurisdiction relinquished.
Notes
. At the conclusion of its opinion, the trial court noted that the charges of false swearing and tampering with or fabricating physical evidence "must also fail for the same reasons stated above for Perjury” (Trial Court Opinion at 16). Subseсtion (c) of the statute defining the offense of false swearing, 18 Pa.C.S. § 4903(c), states that “Section 4902(c) through (f) of this title (relating to perjury) applies to this section.” As there is no similar provision of 18 Pa.C.S. § 4910, which *272 defines the offense of tampering with or fabricating physical evidence, we are unaware of the basis for the trial court’s ruling regarding this offense. However, our resolution of the present appeal makes further consideration of this point unnecessary.
. This citation is incorrect, as the Court is clearly referring to § 4902(f).
. The prison and hospital records were duly proved by the custodians thereof and were received into evidence.
Id.,
332 Pa.Superior Ct. at 150,
