2013 US Code
Title 28 - Judiciary and Judicial Procedure
Appendix (rules 1 - 1103)
FEDERAL RULES OF EVIDENCE (rules 101 - 1103)
Rule 701 - Opinion Testimony by Lay Witnesses

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Publication TitleUnited States Code, 2012 Edition, Supplement 1, Title 28 - JUDICIARY AND JUDICIAL PROCEDURE
CategoryBills and Statutes
CollectionUnited States Code
SuDoc Class NumberY 1.2/5:
Rule 701 - Opinion Testimony by Lay Witnesses
Containsrule 701
Laws in Effect as of DateJanuary 16, 2014
Positive LawYes
Source CreditPub. L. 93-595, §1, Jan. 2, 1975, 88 Stat. 1937; Mar. 2, 1987, eff. Oct. 1, 1987; Apr. 17, 2000, eff. Dec. 1, 2000; Apr. 26, 2011, eff. Dec. 1, 2011.
Statutes at Large Reference88 Stat. 1937
Public Law ReferencePublic Law 93-595

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Opinion Testimony by Lay Witnesses - 28 U.S.C. App § 701 (2013)
Rule 701. Opinion Testimony by Lay Witnesses

If a witness is not testifying as an expert, testimony in the form of an opinion is limited to one that is:

(a) rationally based on the witness's perception;

(b) helpful to clearly understanding the witness's testimony or to determining a fact in issue; and

(c) not based on scientific, technical, or other specialized knowledge within the scope of Rule 702.

(Pub. L. 93–595, §1, Jan. 2, 1975, 88 Stat. 1937; Mar. 2, 1987, eff. Oct. 1, 1987; Apr. 17, 2000, eff. Dec. 1, 2000; Apr. 26, 2011, eff. Dec. 1, 2011.)


The rule retains the traditional objective of putting the trier of fact in possession of an accurate reproduction of the event.

Limitation (a) is the familiar requirement of first-hand knowledge or observation.

Limitation (b) is phrased in terms of requiring testimony to be helpful in resolving issues. Witnesses often find difficulty in expressing themselves in language which is not that of an opinion or conclusion. While the courts have made concessions in certain recurring situations, necessity as a standard for permitting opinions and conclusions has proved too elusive and too unadaptable to particular situations for purposes of satisfactory judicial administration. McCormick §11. Moreover, the practical impossibility of determinating by rule what is a "fact," demonstrated by a century of litigation of the question of what is a fact for purposes of pleading under the Field Code, extends into evidence also. 7 Wigmore §1919. The rule assumes that the natural characteristics of the adversary system will generally lead to an acceptable result, since the detailed account carries more conviction than the broad assertion, and a lawyer can be expected to display his witness to the best advantage. If he fails to do so, cross-examination and argument will point up the weakness. See Ladd, Expert Testimony, 5 Vand.L.Rev. 414, 415–417 (1952). If, despite these considerations, attempts are made to introduce meaningless assertions which amount to little more than choosing up sides, exclusion for lack of helpfulness is called for by the rule.

The language of the rule is substantially that of Uniform. Rule 56(1). Similar provisions are California Evidence Code §800; Kansas Code of Civil Procedure §60–456(a); New Jersey Evidence Rule 56(1).


The amendments are technical. No substantive change is intended.


Rule 701 has been amended to eliminate the risk that the reliability requirements set forth in Rule 702 will be evaded through the simple expedient of proffering an expert in lay witness clothing. Under the amendment, a witness' testimony must be scrutinized under the rules regulating expert opinion to the extent that the witness is providing testimony based on scientific, technical, or other specialized knowledge within the scope of Rule 702. See generally Asplundh Mfg. Div. v. Benton Harbor Eng'g, 57 F.3d 1190 (3d Cir. 1995). By channeling testimony that is actually expert testimony to Rule 702, the amendment also ensures that a party will not evade the expert witness disclosure requirements set forth in Fed.R.Civ.P. 26 and Fed.R.Crim.P. 16 by simply calling an expert witness in the guise of a layperson. See Joseph, Emerging Expert Issues Under the 1993 Disclosure Amendments to the Federal Rules of Civil Procedure, 164 F.R.D. 97, 108 (1996) (noting that "there is no good reason to allow what is essentially surprise expert testimony," and that "the Court should be vigilant to preclude manipulative conduct designed to thwart the expert disclosure and discovery process"). See also United States v. Figueroa-Lopez, 125 F.3d 1241, 1246 (9th Cir. 1997) (law enforcement agents testifying that the defendant's conduct was consistent with that of a drug trafficker could not testify as lay witnesses; to permit such testimony under Rule 701 "subverts the requirements of Federal Rule of Criminal Procedure 16(a)(1)(E)").

The amendment does not distinguish between expert and lay witnesses, but rather between expert and lay testimony. Certainly it is possible for the same witness to provide both lay and expert testimony in a single case. See, e.g., United States v. Figueroa-Lopez, 125 F.3d 1241, 1246 (9th Cir. 1997) (law enforcement agents could testify that the defendant was acting suspiciously, without being qualified as experts; however, the rules on experts were applicable where the agents testified on the basis of extensive experience that the defendant was using code words to refer to drug quantities and prices). The amendment makes clear that any part of a witness' testimony that is based upon scientific, technical, or other specialized knowledge within the scope of Rule 702 is governed by the standards of Rule 702 and the corresponding disclosure requirements of the Civil and Criminal Rules.

The amendment is not intended to affect the "prototypical example[s] of the type of evidence contemplated by the adoption of Rule 701 relat[ing] to the appearance of persons or things, identity, the manner of conduct, competency of a person, degrees of light or darkness, sound, size, weight, distance, and an endless number of items that cannot be described factually in words apart from inferences." Asplundh Mfg. Div. v. Benton Harbor Eng'g, 57 F.3d 1190, 1196 (3d Cir. 1995).

For example, most courts have permitted the owner or officer of a business to testify to the value or projected profits of the business, without the necessity of qualifying the witness as an accountant, appraiser, or similar expert. See, e.g., Lightning Lube, Inc. v. Witco Corp. 4 F.3d 1153 (3d Cir. 1993) (no abuse of discretion in permitting the plaintiff's owner to give lay opinion testimony as to damages, as it was based on his knowledge and participation in the day-to-day affairs of the business). Such opinion testimony is admitted not because of experience, training or specialized knowledge within the realm of an expert, but because of the particularized knowledge that the witness has by virtue of his or her position in the business. The amendment does not purport to change this analysis. Similarly, courts have permitted lay witnesses to testify that a substance appeared to be a narcotic, so long as a foundation of familiarity with the substance is established. See, e.g., United States v. Westbrook, 896 F.2d 330 (8th Cir. 1990) (two lay witnesses who were heavy amphetamine users were properly permitted to testify that a substance was amphetamine; but it was error to permit another witness to make such an identification where she had no experience with amphetamines). Such testimony is not based on specialized knowledge within the scope of Rule 702, but rather is based upon a layperson's personal knowledge. If, however, that witness were to describe how a narcotic was manufactured, or to describe the intricate workings of a narcotic distribution network, then the witness would have to qualify as an expert under Rule 702. United States v. Figueroa-Lopez, supra.

The amendment incorporates the distinctions set forth in State v. Brown, 836 S.W.2d 530, 549 (1992), a case involving former Tennessee Rule of Evidence 701, a rule that precluded lay witness testimony based on "special knowledge." In Brown, the court declared that the distinction between lay and expert witness testimony is that lay testimony "results from a process of reasoning familiar in everyday life," while expert testimony "results from a process of reasoning which can be mastered only by specialists in the field." The court in Brown noted that a lay witness with experience could testify that a substance appeared to be blood, but that a witness would have to qualify as an expert before he could testify that bruising around the eyes is indicative of skull trauma. That is the kind of distinction made by the amendment to this Rule.

GAP Report—Proposed Amendment to Rule 701. The Committee made the following changes to the published draft of the proposed amendment to Evidence Rule 701:

1. The words "within the scope of Rule 702" were added at the end of the proposed amendment, to emphasize that the Rule does not require witnesses to qualify as experts unless their testimony is of the type traditionally considered within the purview of Rule 702. The Committee Note was amended to accord with this textual change.

2. The Committee Note was revised to provide further examples of the kind of testimony that could and could not be proffered under the limitation imposed by the proposed amendment.


The language of Rule 701 has been amended as part of the general restyling of the Evidence Rules to make them more easily understood and to make style and terminology consistent throughout the rules. These changes are intended to be stylistic only. There is no intent to change any result in any ruling on evidence admissibility.

The Committee deleted all reference to an "inference" on the grounds that the deletion made the Rule flow better and easier to read, and because any "inference" is covered by the broader term "opinion." Courts have not made substantive decisions on the basis of any distinction between an opinion and an inference. No change in current practice is intended.

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