Michael J. Hutter
Michael J. Hutter ()

The New York courts adhere to the rule set forth in Frye v. United States, 293 F. 1013 (DC Cir. 1923), in determining the admissibility of expert testimony based upon novel scientific principles or procedures.1 The Frye rule, as explained by the Court of Appeals in People v. Wesley, 83 N.Y.2d 417, 422 (1994), requires the scientific principle or technique to be “sufficiently established to have gained general acceptance in the particular field in which it belongs.” In essence, Frye permits experts who know the most about a principle or procedure to first experiment and then study it, forming a technical jury that must pass upon its status before the jury hears the opinion based upon such principle or procedure.2

The limited purpose of the Frye rule is to ensure the opinion is sufficiently reliable to justify its admission, which is accomplished by the ascertainment of whether the opinion is based upon accepted scientific principles rather than simply the expert’s own unsupported belief, with the goal of “protect[ing] juries from being misled by expert opinions that may be couched in formidable scientific terminology but are based on fanciful theories.”3

By its own words, Frye applies only to the use of novel scientific principles or procedures. Thus, a threshold question in applying Frye is whether the principle or procedure involved is “scientific” and if so, whether it is “novel.” In People v. Oddone, 2013 NY Slip Op. 08291 (Dec. 12, 2013), the Court of Appeals addressed the first part of this question in the context of an expert opinion based on the expert’s personal experience, i.e., what the expert had observed, heard and read about particular cases. The court unanimously held in an opinion authored by Judge Robert S. Smith that expert opinion so derived is not subject to Frye because it is not the product of “science.”4

Notably, the court, having reached such conclusion, then concluded the opinion was properly admitted at trial, strongly suggesting that as the expert was qualified, and the bases relied upon were derived from his personal knowledge, there were no further limitations on non-scientific expert testimony. Given its importance as the ruling was one of first impression for an appellate court in New York, and as well its potential for the allowance of “junk science” opinions, Oddone will be the focus of this column.

‘People v. Oddone’

Defendant was convicted of manslaughter in the first degree for causing the death of the victim by holding him in a headlock. However, the victim’s death was not caused by asphyxiation but was a result of a cardiac arrest resulting from overstimulation of his carotid sinus by the headlock.5 A critical issue in the case was how long defendant held the victim in the headlock.

The prosecution argued that the headlock was maintained for so long, two to four minutes, that defendant must have intended to inflict serious physical injury on the victim; and defendant countered that the victim’s death was a “tragic accident that resulted from the brief application of a headlock that in someone without the victim’s pre-existing medical risk factors ordinarily would be benign.”6 At trial, the testimony as to the duration of the headlock conflicted. The prosecution’s witnesses gave estimates at somewhere near three minutes, and the defense witnesses gave shorter estimates of less than a minute.

In order to prove its contention as predicated upon its witnesses’ testimony as to duration, the prosecution called Dr. James Wilson, a deputy medical examiner. He testified, among other matters, that the victim’s death could only be explained by the application of two to four minutes of neck compression by the headlock. He inferred this duration from two facts: his own observation at the autopsy of “petechiae”—red spots caused by bursting of blood vessels—on and around the victim’s eyes; and the observations of several witnesses that, by the time the incident ended, the victim’s face had turned purple. As to the petechiae, Wilson testified in this exchange:

Q. Could you tell us, Doctor in your experience how long it would take for this type of petechiae to be present…around his eyes, in the skin surrounding his eyes?

A. Well, in my experience and understanding of how this process occurs an injury of this sort would take matter of minutes, 2, 3 perhaps 4, with neck compression [instead of] some kind of a struggle. So there may be slight variations in the pressure from time to time, but matter of a few minutes, something in the range of 2, 3, 4 minutes.

As to the discoloration of the victim’s face, the questioning and testimony continued:

Q. In your opinion, Doctor, how long would it take for the blood in the veins that is not able—that is being squeezed and kept in the head, how long would it take in order for that purple cast or coloration to occur in [the victim's] face?

A. Well, in my opinion and experience the blood that is built up over a period of time, then loss of oxygen, to get very dark it would be a matter of a few minutes minimum, something in the order of 2, 3, 4 minutes.

Oddone, 2013 NY Slip Op. 08291 at *3.

The basis for these opinions as derived from the physical facts as to the victim’s condition was his “personal experience.” This experience, as shown by the record on appeal, but not fully stated in the court’s opinion, consisted of conversations with unidentified “other individuals,” a single unspecified presentation by a former police officer, and “[p]erhaps seeing something on television,” together with his knowledge of biology and medicine. He did not testify that he had experience involving the examination of dead bodies who presented with similar physical conditions as the victim here had.7 Of note, nothing in the medical literature and no medical principle supported his petechiae claim, and the definitive article on the subject which Wilson was unfamiliar with did not at all even remotely support it;8 and as to the “purple face” claim, medical principles established only that a “purple face” can happen very quickly and does not require two to four minutes of neck compression.9

The Court of Appeals held Dr. Wilson’s above challenged testimony was properly admitted. In so holding, the court rejected defendant’s argument that it was admitted in violation of Frye as there was no showing that the principles Wilson relied on—the length of compression required to produce petechiae and purple coloring—to reach his conclusion that the victim’s neck must have been compressed for two to four minutes was shown to have been generally accepted in its field. In the court’s view, Frye was inapplicable because Wilson’s reliance on the petechiae and purple coloring conditions was not reliance upon any scientific principle but rather reliance on his personal experience. Id. at *3-4. Thus, the court drew a distinction between expert testimony based on scientific principles and experience-based testimony, with the former subject to Frye but not the latter. Id. at *4.

Notably, the court acknowledged that “an opinion based on experience alone is ordinarily less reliable than one based on generally accepted science.” Id. While this acknowledgment would ordinarily seem to then require close scrutiny under Frye of such testimony, the court dismissed such a thought. The reason was the court’s belief that any flaws in the testimony which suggest its unreliability can be exposed by cross-examination and by the opinions of opposing experts. Id. So long as the jury is not misled into thinking that the expert’s opinion reflects a generally accepted principle, there would be no “unfairness.” Id.

Principle or Procedure

To understand fully the import of Oddone, analysis starts with how the courts have defined “scientific.” Review of the numerous decisions applying Frye indicates that “scientific” when used as an adjective for principle or procedure means a grounding in the methods and procedures of science, that is, the laboratory methods of investigation, evaluation and verification.10 Thus, Frye has been applied to all areas of “hard science,” such as DNA theory and methodology; engineering analysis; medical mechanism of an injury; and “soft science,” such as social and behavioral theories.11 Whether experience-based expert testimony was “scientific” or “non-scientific” had not been fully explored by the courts before Oddone.12

Exclusion of Experience

The court’s wholesale exclusion of so-called experience-based expert testimony from Frye scrutiny raises numerous issues and problems. Initially, the question of the justification for such exclusion is present. Certainly, when an expert uses his/her experience to reach a conclusion, as Dr. Wilson did, it would appear methods of science are involved as the expert is necessarily making evaluations from information known by or provided to him/her, and/or comparisons between present and past conditions to form an opinion, which are methods and procedures of science. In this connection, an analogy can be drawn to the settled application of Frye to syndrome evidence which is based on how a person may or may not react to a traumatic event as derived from past responses of other persons.13 There is no principled reason to distinguish experience-based opinion from syndrome-based opinion as both involve the same basic evaluation and comparison principles.

Furthermore, the premise underlying the exclusion that an expert’s opinion should be treated more permissibly simply because the expert’s opinion involves his/her “experience” is contrary to Frye’s policy goal of preventing unreliable expert testimony from even being heard by a jury. In that regard, since experience-based expert testimony can certainly raise reliability concerns, it should receive the same Frye degree of scrutiny for reliability as an expert who is using a pure “scientific” method.14 In sum, “[t]here is little justification,” as observed in a leading treatise, “for exempting [opinions based on experience, observation, and study] from close scrutiny…[a]s their reliability is often questionable.”15

How then does the court bypass Frye? It does so by observing initially that experience-based testimony does not have the same aura of infallibility as testimony which is based on an articulated principle or procedure, scientific in nature, and thus does not have the same potential for misleading the jury as does testimony based on a scientific principle or procedure. Id. at *4, citing Flanagan v. State, 625 So.2d 827, 828 (Fla. Sup. Ct. 1993). This observation seems flawed as one could reasonably reach the exact opposite conclusion, especially in Oddone where Wilson was articulating in effect a scientific basis for his opinions. The court’s additional supporting reason that Frye’s goal is not undermined by its holding here because both parties agreed that petechiae and discoloration are caused by neck compression is not compelling because such agreement does not necessarily relate to the opinion’s reliability.

A significant problem raised by the court’s holding is that a line will now have to be drawn between scientific-based testimony and experience-based testimony. Notably, the court acknowledged that it “may not be possible to draw a neat line” distinguishing the two because of the absence of judicial guidance as to exactly what a scientific principle is. Id. at *4. The lack of a “neat” line will inevitably lead to the admission of expert testimony of questionable reliability. While the court sought to minimize the likelihood of this happening, stating “[w]e do not imply that an expert is allowed to say anything he or she likes to a jury if the statement is prefaced by the words ‘in my opinion’,” Id at 4, the lack of any guidelines or factors to consider in making the determination provides no assurance it will not happen.

Other Reliability Standards

Are there standards for assessing the reliability of expert testimony which is not subject to Frye? While the Oddone opinion suggests there are no reliability standards when Frye is inapplicable, there are in fact applicable standards. They are part of the admissibility standard applicable to all evidence—whether there is an appropriate foundation.16 This foundation predicate requires consideration of the extent and quality of the experience, e.g., number of prior encounters, involvement with them, specific enumeration of what was studied, including the literature utilized.17

Furthermore as part of the foundation for his/her testimony the expert will need to explain how his/her experience led to the opinion reached, why that experience is a sufficient basis for the opinion, and how that experience was reasonably applied to the facts.18 This necessarily will involve a determination as to whether the expert’s reasoning in applying his/her experience is flawed because of an “analytical gap between the opinion and the experience relied upon.”19 Lastly, the foundation inquiry will involve consideration of whether the expert’s ultimate opinion has been “rejected outright” by other experts in the relevant field as reliance on mere experience by an expert should not in these circumstances permit admissibility of the opinion.20


Nothing in this column is intended to suggest that experience should not be permitted to support expert testimony. To the contrary, as Oddone clearly holds, experience may properly be utilized by an expert in reaching a conclusion. The practitioner must now be prepared in presenting or defending against expert testimony to determine whether experience-based or science-based is involved. If the latter, Frye must be satisfied; and if the former, Frye is inapplicable but other foundation issues, as discussed above, will have to be addressed.

Michael J. Hutter is a professor at Albany Law School, and is special counsel to Powers & Santola..


1. See generally, Barker and Alexander, Evidence in New York State and Federal Courts (2d ed) §7:5; Martin, Capra and Rossi, New York Evidence Handbook (2d ed) §7.2.3; Prince, Richardson on Evidence (Farrell 11th ed.) §7-311.

2. See, Grady v. Frito-Lay, 839 A.2d 1038, 1045 (Pa. Sup. Ct. 2003) (“We believe now…that requiring judges to pay deference to the conclusions of those who are in the best position to evaluate the merits of scientific theory and technique when ruling on the admissibility of scientific proof, as the Frye rule requires, is the better way of insuring that only reliable expert scientific evidence is admitted at trial.”).

3. People v. Weinstein, 156 Misc.2d 34, 37 (Sup. Ct. N.Y. Co. 1992) (Carruthers, J.).

4. As a result of this conclusion, the court did not address the “novel” sub-part of the issue.

5. People v. Oddone, 89 A.D.3d 868, 869 (2d Dept. 2011).

6. Defendant’s opening Brief in Court of Appeals at p. 4.

7. Oddone, Appendix 3668-3669, 3688-3691, 3693-3697.

8. Id. at 4634-4635; 6967-6971.

9. Id. at 4626-4629, 4633-4635.

10. See, Lugo v. New York City Health & Hosps., 89 A.D.3d 42, 56-57 (2d Dept. 2011); Relihan, “Considering the Frye Rule in New York,” NYLJ, Sept. 15, 2000, p. 24, col. 6; see also, Daubert, 509 U.S. at 590.

11. Barker, supra, §7.5 at p. 14; Martin, supra, §§

12. See, Saulpaugh v. Krafte, 5 A.D.3d 934 (3d Dept. 2004), lv. den. 3 N.Y.3d 610 (2004) (suggesting Frye applicable where experience involved).

13. See, People v. Taylor, 75 N.Y.2d 277, 285-287 (1990) (rape trauma syndrome evidence admissible when offered to explain behavior exhibited by the complainant that might be viewed as inconsistent with a claim of rape).

14. See, Advisory Committee Notes to 1972 Proposed Amendments to FRE Rule 702, citing Watkins v. Telsmith, 121 F.3d 984, 991 (5th Cir. 1997) (“[I]t seems exactly backwards that experts who rely on general engineering principles and practical experience might escape screening by the district court simply by stating that their conclusions were not reached by any particular method or technique.”).

15. Giannelli, Scientific Evidence (5th ed) §1.06(d).

16. See, Parker v. Mobil Oil, 7 N.Y.3d 434, 447 (2006).

17. See, Barker, supra, §7.5 at pp. 16-17 (collecting cases).

18. See, Advisory Committee Notes, supra.

19. Martin, supra, §7.2.5 at pp. 611-612.

20. Marso v. Novak, 42 A.D.3d 377, 378 (1st Dept. 2007), lv. den., 12 N.Y.3d 704 (2009).