OPINION
This opinion addresses the question whether an agent of the FBI can testify as a forensic stylistic expert and whether forensic stylistics is a rehable technique to allow the expert to identify Defendant as the author of unidentified threatening letters.
This matter comes before the Court on the Defendant’s in limine motion to exclude the testimony of the Government’s expert witness FBI Special Agent James R. Fitzgerald (“Fitzgerald” or “Agent Fitzgerald”). For the reasons set forth below, the Court grants in part Defendant’s motion to exclude Fitzgerald’s testimony by limiting his testimony to the comparison of characteristics or “markers” between handwritten and typеd writings, in which Defendant is known to be the author (“known writings”) and the handwritten and typed writings, in which authorship is “questioned” or unknown (“questioned writings”). Fitzgerald’s testimony regarding any “external” or extrinsic factors and his conclusion as to the author of the “questioned” writings are barred.
I. BACKGROUND
Defendant Roy Van Wyk (“Defendant”) has been charged with a four count Su *517 perseding Indictment. Count One alleges that from January 1993 through December 1998, Defendant conspired to make threatening communications in violation of 18 U.S.C. § 875. Counts Two and Three allege two specific instances of threatening communications made tо victims “MJ” and “GW.” Count Four charges Defendant with possession of a firearm by a convicted felon in violation of Title 18 U.S.C. § 922(g)(1) and (2). 1
Defendant seeks to exclude the proposed expert testimony of Agent Fitzgerald. Fitzgerald testified at a F.R.E.Rule 104 evidentiary hearing on February 3, 2000. 2 The Government presents Agent Fitzgerald as an expert in forensic stylistics, 3 an area of scientific expertise which the Government has conceded is novel. (February 3, 2000 Hearing Transcript (“Hearing Tr.”), at 179.) Forensic stylistics is the examination of writing style “for the express purpose of resolving litigated questions rеlated to disputed authorship or meaning.” McMenamin, G. Forensic Stylistics, 58 Forensic Science Int’l, 1, 45 (1993) (hereinafter “McMenamin article”). More specifically,
[i]n cases of disputed authorship, the linguist analyzes and describes the style of writing of a document of questioned authorship and compares and contrasts its language to that of documents known to be written by a given author.
Id. at 3.
For purposes of this motion, it is helpful to divide Fitzgerald’s opinion into three components: (1) internal evidence, which is actual comparisons of similarities or “markers” within the “four corners” 4 of the known and questioned writings; (2) external or extratextual evidence, such as “known dates of composition, date and location of mailing, DNA evidence, and the like”; 5 and (3) opinion that the author of all the questioned writings is the same individual and that Defendant is that author.
Defendant argues that Agent Fitzgerald is not qualified to testify as a forensic stylistics expert. Defendant notes that no expert has yet testified in the area of linguistic stylistics, indicating its lack of reliability. Moreover, the jury is capable of comparing samples of writings without Fitzgerald’s testimony.
II. DISCUSSION
A. Standard Governing Admissibility of Expert Opinions
Federal Rule of Evidence 702 gоverns the admissibility of expert testimony and provides that:
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.
*518
Fed.R.Evid. 702. The Rule therefore has three fundamental requirements: (1) the proffered witness must qualify as an expert by knowledge, skill, experience, training, or education; (2) the expert must testify to scientific, technical, оr other specialized knowledge; and (3) the expert’s testimony must assist the trier of fact.
United States v. Velasquez,
The Third Circuit has interpreted the first requirement of Rule 702 liberally.
See e.g., In Re Paoli R.R. Yard PCB Litig. (“Paoli
I”),
The proposed expert must possess knowledge, skill, experience, training,
or
education in the area of his оr her testimony greater than the average layperson.
See Aloe Coal Co. v. Clark Equipment Co.,
The Third Circuit has held that it is an “abuse of discretion to exclude testimony simply because the trial court does not deem the proposed expert to be the best qualified or because the proposed expert does not have the specialization the court considers most appropriate.”
Holbrook v. Lykes Bros. S.S. Co., Inc.,
“The second requiremеnt of Rule 702— that’ the expert testify to scientific, technical or other specialized knowledge' — is intended to ensure the reliability or trustworthiness of the expert’s testimony.”
Velasquez,
When рresented with a proffer of expert “scientific” testimony, the court must make a “preliminary assessment of whether the reasoning or methodology underlying the testimony is scientifically valid.”
Daubert,
Finally, the Court must consider the third requirement, whether the expert’s testimony will “assist the trier of fact” to understand evidence or determine a fact in issue. This requirement goes primarily to relevance.
Daubert,
The party seeking to admit expert testimony “bears the burden of establishing its admissibility by a preponderance of proof.”
Schmaltz v. Norfolk & Western Railway Co.,
In assessing a proffer of expert scientific testimony under F.R.E.Rule 702, the Court must alsо consider other applicable rules such as F.R.E.Rule 4,03, which “permits the exclusion of relevant evidence ‘if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury ... ’ ”
Daubert,
B. Analysis
1. Qualification as an Expert
Agent Fitzgerald is a member of the National Center for the Analysis of Violent Crimes (“NCAVC”) unit of the FBI Academy in Quantico, VA. See Fitzgerald Curriculum Vitae (“Fitzgerald CV”), at 1. He has been in that unit for about five years. Ibid. As evident from the name of the group, the NCAVC’s role is to aid in solving violent crime or violent crime-related matters. Hearing Tr. at 110. Agent Fitzgerald does not have a degree in linguistics, forensic stylistics, or text analysis; he has a bachelor’s degree in criminal justice and a master’s degree in criminal justice administration. Ibid. He has, however, among other things, attended threat assessment, psychotherapy assessment, and risk assessment seminars that have in *520 volved matters related to the assessment of text, id. at 111-12, taught and conducted research in text analysis, id. at 115-19, analyzed text on a weekly or even daily basis during the course of his five years at NCAVC, id. at 113, and has worked on text analysis in a number of high profile matters including the Unabomber case. Id. at 121-27.
Defendant contends that Fitzgerald is not qualified as an expert because he only began receiving specialized training in forensic stylistics in 1998, that he has attended only three seminars in this area, and that he has only performed between ten and twelve document analyses to determine authorship. Defendant’s Supplemental Memorandum in Opposition to the Proposed Expert Testimony Of James Fitzgerald, at 13.
As evidenced by testimony during the evidentiary hearing, however, since 1998, Fitzgerald has had rather extensive experience in text analysis, having observed and studied text for years. He arguably qualifies as an “observational” expert because he has examined so many examples over an extended period of time.
Cf. United States v. Hines,
Defendаnt is, of coursé, entitled to cross-examine Fitzgerald vigorously as to his expertise, or alleged lack thereof, and to his methods used to reach his conclusions. These issues more properly go to the credibility of Fitzgerald’s testimony and the weight the jury should give it, rather than to its admissibility.
See Gisriel v. Uniroyal Inc.,
2. Reliable Scientific Testimony Aiding the Jury
Defendant also claims that the proffered expert testimony is subjective, unreliable, and lacks measurable standards. Unfortunately, no case law, 6 treatise, or law review article has dealt with this precise issue of whether the examination of text analysis to resolve a litigated question related to disputed authorship or meaning, or forensic stylistics, constitutes sufficiently reliable scientific evidence admissible in court.
Under the
Daubert
standard, one of the pertinent considerations in determining whether a theory or technique is scientific knowledge that will assist the trier of fact is whether the theory or technique has been subject to peer review and publication. Publication is but one element of peer review.
Daubert,
*521 . The Government has cited to one publication 7 dealing with forensic stylistics— the McMenamin article. 8 That article explains:
[linguistics is a well established scientific discipline with a long history of inquiry, and linguistic stylistics is the field within this discipline that studies variation in written language ... Stylistics is an applied science in two senses. It first requires an application of formal linguistic theory to empirical (fact-finding) linguistics, and second involves application of factual linguistics to the “applied” field of stylistics, thus fulfilling human purposes related to text description and interpretation or author identification.
McMenamin article, at 48. “To the extent that variatiоn in written language can be measured, stylistics incorporates statistics.” Id. at 50. 9 According to the McMe-namin article, the results of stylistic analysis can be precise, coherent, and relatively complete; additionally, when objective stylistic analysis is restricted to demonstrable or measurable facts, it "will produce reliable results. McMenamin article, at 48-49. The McMenamin article also notes that there is not one generally accepted technique of stylistic analysis; the decision depends largely on the data presented. Id. at 49. Furthermore, although there are those in the scientific community who view the concept of style as defying analysis, “the scientific community overwhelmingly accepts that style is present in all written texts and that it can be observed, described, and analyzed.” Id. at 50. Due, however, to the dearth of published cases or journals addressing forensic stylistics, the novelty of this field, and the fact that it has only been approved by law enforcement, the Court has no way of determining whether the McMenamin article is merely self-legitimized. 10
Fitzgerald testified to the specific methodology he uses in determining authorship. First, he normally separates and catalogs the writings either chronologically or by victim. Hearing Tr. at 132. In this case, because there were handwritten and typewritten writings, he divided them into four categories: Known Typings (“KT”), Known Writings (“KW”), Questioned Typ-ings (“QT”), and Questioned Writings (“QW”). Ibid. Then he read the twenty-two letters to obtain a sense for the “feel” of the writings. Ibid. Third, he color coded the issues contained in the writings into four categories: (1) punctuation and spelling; (2) threat; (3) interesting phrases; and (4) correct or incorrect “trip” phrases such as use of “there” or “their,” use of “to,” “two,” or “too,” and “your,” or “you’re.” Id. at 133-34. Next, Fitzgerald created a chart and determined whether a particular word, abbreviation, or phrase *522 was used correctly or was an idiosyncracy. Id. at 134. His results were reviewed by two other law enforcement officers. Id. at 114. No sources outside the FBI have reviewed his reports. Id. at 157.
Although Fitzgerald employed a particular methodology that may be subject to testing, neither Fitzgerald nor the Government has been able to identify a known rate of error, establish what amount of samples is necessary for an expert to be able to reach a conclusion as to probability of authorship, or pinpoint any meaningful peer review. Additionally, as Defendant argues, there is no universally recognized standard for certifying an individual as an expert in forensic stylistics.
Various judicial decisions regarding handwriting analysis, while not identical to text analysis, are instructive because handwriting analysis seems to suffer similar weakness in scientific reliability, namely the following: no known error rate, no professional or academic degrees in the field, no meaningful peer review, and no agreement as to how many exemplars are required tо establish the probability of authorship.
See Hines, 55
F.Supp.2d at 69;
United States v. Santillan,
In Hines, the court permitted the government’s handwriting expert to testify regarding the similarities and dissimilarities between the defendant’s handwriting and handwriting on a robbery note, but did not allow the expert to testify to the identity of the defendant as the author of the robbery note. In so holding, the court recognized not only the lack of reliability of the handwriting expert testimony, e.g. no known rate of error or established standard, but also that the jury could easily evaluate on its own the similarities between the handwriting samples. The court noted, “[t]his is not rocket science, or higher math.” Hines, 55 F.Supp.2d at 70. Nevertheless, the court was unwilling to disallow expert testimony altogether because the handwriting expert testimony
involves more than just identifying what is similar and what is different in the same way a lay person would. It involves taking the next step — that this or that similarity matters, that it equals a general pattern. Presumably, the expert is helped in drawing general patterns by the numbers of exemplars she has seen, just like the spouse identifies the husband’s handwriting because she has seen it numbers of times.
Id.
at 70 n. 21. The court determined, however, that the expert’s conclusion of authorship would be extraordinarily prejudicial. In its analysis, it noted that the court in
United States v. McVeigh,
“there is a great difference between a witness who has the requisite training and skill saying, ‘Look, I’ve compared this handwriting on this exhibit with this exemplar and I’ve used the techniques of microscoping (sic) and, you know, all of those things that are often involved in that kind of comparison, and these are the things I find,’ and T see these similarities and these dissimilarities and so forth’ but does not go on to reach any sort of ultimate conclusion that this was written by the same person or expresses some probability or degree of confidence. The problem with ... handwriting is that there is no testing of the — no verification-type testing of these opinion results; and in addition, there has never been within the discipline of people who practice this skill — there has never been any agreement on how to express the results. There is no standardized nomenclature, you know. Therefore, it seems to me that we should draw the distinction between somebody getting on the stand and saying ‘Yeah, written by the same person,’ or ‘no, not written by the same persоn,’ vs. ‘these are the simi *523 larities or these are the dissimilarities’; and the jury can decide.”
Id.
at 70 (citing
McVeigh,
In accordance with
Hines
and
McVeigh,
the district court for the Northern District of California, also ruled that the handwriting expert’s testimony as to the “specific mechanics and characteristics of handwriting” was admissible.
Santillan,
i. Fitzgerald’s Opinion on Authorship of Writings
The Court agrees with the rationale and approaches utilized in
Hines, McVeigh,
and
Santillan.
The reliability of text analysis, much like handwriting analysis, is questionable because, as discussed
supra,
there is no known rate of error, no recognized standard, no meаningful peer review, and no system of accrediting an individual as an expert in the field. Consequently, the existing data for forensic stylistics cannot definitively establish, as can DNA data, that a particular person is “the” author of a particular writing.
Cf. Hines,
Because of the lack of scientific reliability of forensic stylistics, the Court is not satisfied that the jury would benefit from Fitzgerald’s testimony as to his subjective opinion that the questioned writings were written by the same individual and that that individual is Defendant Roy Van Wyk. Moreover, the fact that such a conclusion comes from an “expert” may place more weight and credence on Fitzgerald’s opinion than is warranted. Acknowledging Fitzgerald’s opinion as that of an expert and FBI agent invests the opinion with an objectivity that this methodology does not support. In weighing its prejudicial effect compared to its probative value, exclusion is warranted. Because the opinion testimony is substantially more prejudicial than it would be probative, it should be excluded under F.R.E. Rule 403. Therefore, Agent Fitzgerald is not permitted to testify to his conclusion as to the identity of the author of the unknown writings.
•ii. Internal Evidence Testimony
As the Government states, there can be no question that evidence of the known writings and unknown writings is admissible; courts uniformly have admitted evidence of known writings, recognizing that the particular or peculiar use of grammar and spelling, for example, can be observed and identified to establish authorship.
See Clifford,
The question here is whether the Court may properly allow Agent Fitzgerald to testify as an expert regarding the comparisons of markers between the known writings and questioned writings.
11
Defendant argues that Agent Fitzgerald’s expert testimony will not be helpful in assisting the trier of fact. He argues that comparisons between the known and questioned writings could easily be drawn by the jurors and that such expert testimony would only overwhelm, confuse or mislead the jury. Unlike his opinion on authorship, Fitzgerald’s expertise in text analysis can be helpful to the jury by facilitating the comparison of the documents, making distinctions, and sharing his experience as to how common or unique a particular “marker” or pattern is.
See Hines,
iii. External Evidence Testimony
Finally, Defendant objects that Agent Fitzgerald draws his conclusion not only from documents submitted to him, but also on “a review of the history of Van Wyk and the victimology of the four women who were recipients of one or more of these documents.” Fitzgerald report, at 15. That is, Defendant claims the proposed expert’s opinion relies on “external” and background information, the sum of which is to cast Defendant as a “terrorizer” of women, or as a “very bad” person. Fitzgerald in effect states that Van Wyk is the author because he is the aggressor, whereas the issue is whether he is the aggressor because he is the author. The Court agrees with Defendant and finds that such external factors are actually “disguised” propensity evidence, which is prohibited by F.R.E. Rule 404(b). Accordingly, Fitzgerald’s testimony regarding these external or extratextual factors is barred. The jury has already heard that evidence. For Fitzgerald to repeat it as an expert is highly prejudicial and F.R.E. Rule 403 аlso precludes it.
III. Conclusion
For the foregoing reasons, Defendant’s motion in limine to exclude Fitzgerald’s testimony is granted in part; Fitzgerald’s expert testimony is limited to the comparison of characteristics or “markers” between writings known to have been authored by Defendant and the writings in which authorship is “questioned” or unknown. Fitzgerald’s testimony regarding any “external” or extrinsic factors is barred as is his conclusion regarding the identity of the author of the “questioned” writings.
An appropriate Order follows.
ORDER
This matter having come before the Court on Defendant’s in limine motion to *525 exclude the proposed expert testimony of FBI Special Agent James R. Fitzgerald; and
The Court having considered the submissions of the parties; and
The Court having heard oral argument from the parties on February 3, 2000 and February 4, 2000; and
For the reasons set forth in the Court’s Opinion issued this day; and
For good cause shown;
It is on this the 5th day of February, 2000 hereby ORDERED that Defendant’s motion in limine is granted in part and denied in part; and
IT IS FURTHER ORDERED that Agent Fitzgerald may testify to the comparison of characteristics or “markers” between the handwritten and typed writings, of which Defendant is known to be the author, and the handwritten and typed writings, of which authorship is “questioned” or unknown; and
IT IS FURTHER ORDERED that Fitzgerald’s testimony regarding any “external” or extrinsic factors and his conclusion as to the author of the “questioned” writings are barred.
Notes
. By Order dated January 12, 2000, the Court severed Count Four from the other counts.
. On February 4, 2000, after the conclusion of a jury charge conference, counsel made additional arguments as to the admissibility of Agent Fitzgerald's testimony.
. At oral argument on February 4, 2000, the Government withdrew its proffer of Agent Fitzgerald as an expert in forensic stylistics and instead proffered him as an expert in text analysis. Forensic stylistics and text analysis both involve the examination of text or writing style; the only difference that the Court can glean between forensic stylistics and text analysis is that forensic stylistics is specifically geared towards resolving litigated questions related to disputed authorship or meaning.
. The four primary categories are: punctuation, orthography or spelling, grammar, and “other.” Hearing Tr. at 130. For example, in some of the questioned typed writings, Fitzgerald notes that with respect to the use of an apostrophe in a possessive word or in a contraction, the writer either completely omits the apostrophe or instead substitutes improper punctuation, such as a comma or quotation mark. Fitzgerald Report, at 10-11.
. Fitzgerald Report, at 2.
. The Court is aware of only three cases in which forensic stylistiсs has been addressed. In the first case,
United States v. Clifford,
. Although the Government also states that a chapter on forensic stylistics in included in a treatise by Cyril H. Hecht, entitled Forensic Sciences, it has not yet been able to obtain a copy of that treatise.
. The same text has also been published in a book entitled Forensic Stylistics.
. In
Clifford,
. The following quote from the McMenamin article does little to instill confidence in the reliability of the Agent’s opinion as to authorship:
There is strong practical and theoretical motivation to combine available methodologies in the analysis of style. From the researcher’s perspective, the obligation to explain his or her method and findings leads to conclusions that are "not so much objective as they are ‘intersubjective.’ ” (Ross 1973:3). With respect to the linguistic data itself, the study of stylistic variation mediates (in a relation of complementarity) between the non-measurable (qualitative) linguistic variables, which are the rules of language, and the measurable (quantifiable) frequencies of occurrence of units exemplifying the values of those linguistic variables (Itkonen 1980:363) (emphasis added).
McMenamin article, at 170.
. During the evidentiary hearing on February 3, 2000, defense counsel conceded that he would have no objection to Agent Fitzgerald testifying about the internal evidence. Hearing Tr. at 189. The next day, however, counsel for Defendant changed his position by withdrawing this concession.