Sunday, April 01, 2007

Still More on Ramirez

Stimulated by James England's thoughtful analysis in this space, we've devoted more thought to the Colorado Supreme Court's decision last week in People v. Ramirez, and we have the following questions and observations, all of them untainted by any deep acquaintance with Colorado evidence law:

(1) What is the real scope of any tension between Ramirez and the same court's 2005 decision in People v. Wilkerson?

Wilkerson, it will be recalled, involved an ergonomics expert who proposed to testify, on behalf of a criminal defendant, that a shooting was unintentional. At a pretrial hearing, the expert opined that the shooting was "more likely than not" accidental. He explained, on cross-examination, that by that opinion, he meant there was more than a 50% probability that the shooting was unintended. In arguing for the testimony's admissibility, defense counsel likewise characterized it as an opinion that under conditions described by the witness, an accidental shooting could happen 51% of the time. Understanding the expert to be offering a statistical characterization, and concluding that the statistical characterization did not enjoy reliable support, the trial court barred the witness from offering testimony that the shooting was more probably than not accidental. The trial court did not rule on the defendant's alternative proffer -- qualitative testimony to the general effect, as defense counsel put it, that "the best minds that study this sort of thing and study stress, and study systems and human factors and study handguns, and have written articles about this sort of thing say that, yes, accidental shootings can happen."

On interlocutory review, the Colorado Supreme Court upheld the trial court's ruling, concluding that the trial court could permissibly have excluded the "more likely than not" opinion under Colo. R. Evid. 403, and also that the expert had offered insufficient support, under Colo. R. Evid. 702, for a quantitative assessment. The high court said:
Given the preciseness of the district court’s order, rejecting an expert conclusion expressed in terms of quantifiable, scientific test results, the court’s emphasis on the expert’s failure to test a specific weapon and the absence of peer reviewed literature concerning standards for measurement and error rates did not evidence a misunderstanding of the flexible test we described in [People v. Shreck, 22 P.3d 68, 78-79 (Colo. 2001) (rejecting Frye in favor of a more Daubertian approach)]. Rather than excluding expert opinion merely because it was incapable of quantification, the district court was faced with an opinion expressed in numeric terms, and it appears to have considered precisely those factors most applicable to the admissibility of such a numeric test result.
Given the trial court's failure to rule on the defendant's alternative proffer, the Wilkerson court expressed "no opinion concerning the reliability or relevance of any other proffered testimony of the defense expert."

We1 voiced some dismay when the Wilkerson opinion was first issued. The basis for that dismay was our perception that the trial and appellate courts in Wilkerson may have fallen prey to a fairly common intellectual parlor trick, in which the "probability" concept goes into the hat in the form of a general qualitative standard for expert confidence or the burden of persuasion (the handkerchief), only to emerge later as a term of technical statistical art (the rabbit). This maneuver is sometimes employed in toxic tort litigation to insinuate a defense-friendly requirement that individual causation be proved by odds ratios reaching some specific numerical threshold. It might be called the Probability Pivot, and it generally proceeds in several well-defined steps:
(a) The expert states some opinion.

(b) The expert is asked on cross (at deposition or during a pretrial hearing on admissibility, or perhaps even at trial) to confirm that the expert holds the opinion to the requisite degree of confidence under the law of the relevant state (e.g., "a reasonable medical probability") or that the expert's conclusion satisfies2 the preponderance test for sufficiency of the evidence (e.g., "more likely than not").

(c) The expert complies, often without the questioning having placed the expert on clear notice that the expert's response will later be taken as importing some numerical or statistical standard.

(d) The objecting party then complains that the expert's opinion is not supported by evidence that would establish the opinion as "probable" or "likely" in any numerical or statistical sense.

(e) Alternatively, the expert declines the cross-examiner's invitation to characterize his or her opinion in terms of likelihood or probability, in which event the objecting party complains that the opinion does not satisfy the operative legal requirements for confidence or sufficiency (a step in which those requirements are sometimes conflated with Daubert's reliability standard).
We call this a parlor trick because neither expert confidence requirements nor tests for sufficiency have traditionally been understood in statistical terms, if occasional metaphorical glosses are left to one side. There may be tenable policy arguments for adopting quantitative tests as the substantive standard for certain elements of proof in particular areas of the law. But if so, those policy arguments should be presented to the appropriate governmental branch (the legislature, we're inclined to think) in candid and transparent form -- not smuggled into the decisional law via category mistakes abetted through free-wheeling use of the thesaurus (whether by the judiciary or by attorneys conducting cross). So too, there may be some forms of expert testimony that should not be counted as reliable if specific standards of quantitative analysis go unmet. These may include testimony from experts whose discipline normally requires the use of quantitative methods. Most would also agree that testimony presenting the expert's conclusions in quantitative terms (like the ergonomist's opinion in Wilkerson, as the trial and appellate courts understood it) falls in this category. Our dismay over Wilkerson arose from a worry that the expert was lured unwittingly into quantitative testimonial territory through sneaky cross-examination -- a possibility to which the trial and appellate courts in Wilkerson seemed to us to give unduly short shrift.

But unlike us, the courts in Wilkerson did enjoy access to the record, and they concluded that the opinion was being offered in terms intended to carry quantitative, statistical meaning -- indeed, that proponent's counsel had defended the opinion in those very terms. This being so, the holding in Wilkerson would seem rather narrow. Where a party offers testimony held out as supporting a statistical or quantitative conclusion or inference, the testimony should enjoy a reliable basis in methods or techniques supporting the relevant statistical or quantitative conclusion or inference. Neither the trial court nor the Colorado Supreme Court in Wilkerson, remember, ruled on how the reliability of the alternative, qualitative proffer should be assessed. Neither court in Wilkerson purported to hold, in other words, that common law standards for expert confidence, whether or not they survived adoption of Rule 702, carried any inherent implications for the modern reliability calculus.3

We remain unconvinced, in short, that Ramirez particularly implicates Wilkerson, except in the thin sense that all decisions under an evidentiary regime informed by Daubertian principles are grist for debate over how stringently reliability should be tested, and via what methods. In both cases, we note, a trial court's reliability decision was ultimately affirmed, in keeping with the principle (familiar from federal evidentiary jurisprudence and apparently followed in Colorado as well) that trial courts' reliability determinations are discretionary and entitled to substantial deference. Both decisions also happen to comport with the general de facto principle that in criminal cases, the prosecution's expert testimony almost invariably comes in, whereas the defendant's quite possibly doesn't.

(2) Is the Ramirez court's invocation of Rule 705 really suspect?

Lacking access to the record or briefing in Ramirez, we cannot be sure what argument the defendant/appellant may have raised on appeal about the foundation of the nurse practitioner's testimony. The word "foundation" can be used to denote two slightly different things: (a) the support shown for an expert's opinion in the context of an admissibility inquiry (e.g., during voir dire); or (b) "foundation" testimony offered at trial for consumption by the trier of fact. It is unclear to us, from the Ramirez opinion, how much of the nurse practitioner's testimony defending the reliability of her opinion occurred in each of these respective contexts. But the two contexts are not generally coextensive. If the defendant's argument on appeal was that the testimony offered to the jury did not sufficiently establish the "foundational" predicates for reliability under Rule 702, then Rule 705 would seem a correct (if incomplete) rejoinder. Admissibility determinations are for the court, not the jury. They need not be based on record evidence, and record evidence, for its part, need not recapitulate the predicates for admissibility. Where "reliability" issues have been determined to pose questions of weight rather than admissibility, Rule 705 sensibly permits the trial court to leave their detailed exploration to cross-examination. For the federal courts, at least, requiring that Rule 702 "reliability" be established on direct examination at trial would represent a substantial innovation -- one that would seemingly require amendment of several evidentiary rules, including Rule 104(a).

3. How thin, actually, was the support for the reliability of the nurse practitioner's opinion?

We don't pretend to expertise in this area, and to repeat, we haven't studied the briefing or the record in Ramirez. So it's best we tread cautiously. That said, we find little occasion to doubt the reliability of a nurse practitioner's conclusion that the results of a physical examination were "suspicious," where he or she: (a) examined a ten-year-old child 41 days after an alleged sexual assault and found a healing laceration; (b) had conducted about 90 similar previous examinations; and (c) had reviewed at least some literature on the subject. To us, this seems like the exactly the sort of report, reflecting the educated clinical judgment of a medical professional, that doctors and patients routinely credit, to one degree or another, in nonlitigious contexts, even where the report enjoys no stronger bases than the nurse practitioner's opinion here. It also seems to us that the failure of an earlier examination to find signs of sexual assault is the sort of point that juries are quite competent to assess.

We do admit to some unease, especially in the criminal context, over the presentation of expert opinion that some fact -- although not sufficient, by itself or in combination with other facts, to support an actual finding by the expert on the point -- is "suspicious." Our unease would be still greater if the "suspicious" datum were that the accused had been seen outside the bank a few days before the robbery, twirling his mustache. Our disquiet on this front, however, springs mostly from anxiety over the idea of sending people to jail for being suspects. That, perhaps, is more a sufficiency concern, to be evaluated in individual cases by reference to the entire record, than a reliability one.

1 The editorial "we" refers here to the voice of Blog 702. We mean to ascribe no views, one way or the other, to James England.

2 Sufficiency, of course, is actually a distinct issue from reliability, and one properly evaluated by reference to the entire record, not the testimony of one single witness.

3 The conclusion that the rules of evidence displaced common law standards for expert confidence seems eminently defensible to us, but the issue does not appear to have been presented or addressed in Wilkerson.



Post a Comment

<< Home

Fed. R. Evid. 702: 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, if (1) the testimony is based upon sufficient facts or data, (2) the testimony is the product of reliable principles and methods, and (3) the witness has applied the principles and methods reliably to the facts of the case.