Court Opinion

ID: 9793607
Source: CourtListenerOpinion
Date Created: 2023-08-31 02:50:28.414048+00
Date Added: 2024-06-11T08:06:14.341075
License: Public Domain

GORDON, Justice
(concurring in part, dissenting in part):
Although I concur with the majority on the Miranda and jury instruction issues, I dissent from their position on the closing argument and Dr. Campbell’s testimony.
At the close of his argument to the jury, the prosecutor stated:
“You’re turning this man loose and he will walk out the door, ladies and gentlemen, and as I said before, the evidence suggests in this case a total lack of regard for human life, such a lack of regard, ladies and gentlemen, if you don’t expect such a crime could happen, or that a criminal necessarily, in committing such a crime as this, necessarily is going to stop at just this one death, you better think about that before you come in this courtroom and say not guilty. You think about that evidence I have presented to you—it’s an important matter, * * * it’s very important for the rest of the lives in this community. Very important.”
Clearly this type of argument preys on the fears of jurors, inviting them to prevent hypothetical future crimes by this defendant even though the evidence as to the crime charged may not be beyond a reasonable doubt. Although we have not previously considered this precise argument, an analogous situation was presented in State v. Makal, 104 Ariz. 476, 455 P.2d 450 (1969). There the prosecutor asked the jury to disregard insanity as a defense because
“He is essentially dangerous to other people; he is very dangerous to himself. We can’t afford—society can’t afford to have Mr. Makal take the life of any other innocent victims. * * * Don’t arrive at a verdict which will give Mr. Makal the opportunity to kill again.” Id. at 478, 455 P.2d at 452.
*260In Makal, Justice Struckmeyer reversed, quoting Farris v. Commonwealth, 209 Va. 305, 163 S.E.2d 575, 577 (1968):
“When evidence introduced is not of a subsequent act but of a possible future act, it does not shed any material light on an accused’s mental state at the time of the offense charged. It can only have relation to the possibility or even probability that an accused will in the future commit a criminal act or will be a danger to society, and such evidence tends to destroy by fear the recognized defense of not guilty by reason of insanity.” State v. Makal, 104 Ariz. at 477-478, 455 P.2d at 451-452.
“Evidence of what defendant’s future conduct might be could only serve to divert the attention of the jurors from the real issue in the case * * Farris v. Commonwealth, supra at 577.
Obviously the prejudicial effect is the same regardless of whether the prosecutor urges the jury to disregard the state’s burden of proof or the defendant’s insanity defense. See, e. g, Grant v. State, 194 So.2d 612 (Fla.1967); Lime v. State, 479 P.2d 608 (Okl.Cr.1971); Potter v. State, 511 P.2d 1120 (Okl.Cr.1973). Furthermore, I cannot sanction an argument which is unsupported by the evidence properly before the jury. See DR 7—106(C)(1), Rule 29(a), 17A A.R.S.; State v. Filipov, 118 Ariz. 319, 576 P.2d 507 (1977).
I agree with the majority that “[a]n expert is one whose opinions depend upon special knowledge with which he can assist the jury.” In fact, it is precisely because the value of an expert’s opinion lies in his mastery of a field that will aid the jury that I am unable to agree with the majority’s conclusion on the admissibility of the evidence probability presented by Dr. Campbell.
A reading of Dr. Campbell’s testimony reveals that, not only did he not perform any of his own mathematical calculations in reaching the eight in one million figure, but also that he was unaware of the formula utilized to arrive at that figure other than that it was “computerized”, and that he was ignorant of the statistical weight assigned to each variable used in the equation. (See discussion below). In short, it is obvious that while Dr. Campbell may have a great deal of expertise in the actual comparison techniques of bite-mark identification, he is totally out of his field when the discussion turns to probability theory.
Since Dr. Campbell was able to testify that the figure was obtained from articles and books in the field, the majority presses into service the newly adopted hearsay exception for “learned treatises” to justify admission of the testimony, in spite of Dr. Campbell’s lack of expertise. The majority’s theory is apparently that so long as probability studies have been performed and published in the past by experts in the practical application of probability theory, it is not necessary that the expert on the witness stand be capable of independently generating the results reached by the published study. I cannot agree.
Preliminarily, I have serious reservations as to the applicability of Rule 803(18) 17A A.R.S. After discussing the circumstances in which statements contained in learned treatises are admissible, the last sentence of Rule 803(18) reads as follows, “If admitted, the statements may be read into evidence but may not be received as exhibits.” It seems to me that this sentence qualifies the exception with a requirement that the articles and books within which the relevant statements are contained be physically present in the courtroom and that the witness read the statement directly from the book. Of course, this construction of the sentence does nothing more than affirm the well established requirement that the contents of a writing be proven by production of the original writing. Arizona Rules of Evidence, Rule 1002 17A A.R.S. See also Rule 1001(3) 17A A.R.S. for the definition of “original”.
Dr. Campbell’s testimony provides a classic example of why a witness’ memory of the contents of a writing is not a preferred method of proving those contents. As indicated in the majority opinion, Dr. Campbell was unsure as to precisely where he obtain*261ed the figure “eight in one million”. My independent research reveals that of the two treatises which he could name as containing statistical information, only Warren and Harvey, Dental Identification and Forensic Odontology (1976) lists any figures on the uniqueness of a bite-mark. Rather than the eight in one million figure vouched for by Dr. Campbell, though, that treatise, at page 139, contains the figure eight in one hundred thousand.1
Assuming that the jury took seriously Dr. Campbell’s “eight in one million” apparently erroneous probability figure, and further assuming that the members of the jury tried it out on the estimated population of Pima County at the time of trial (approximately 465,000)2 it would come to the conclusion that only 3.72 people in Pima County could make teeth marks similar to those found on the victim’s body. If, however, the figure eight in one hundred thousand is the correct figure, there would be thirty-seven people in Pima County whose teeth could make similar marks. This example graphically illustrates just one of the reasons I am so concerned about allowing such unfounded probability figures into evidence—a little error can paint a drastically distorted picture. The other reason is that the stunning impact of dramatic figures makes the picture indelible in the minds of the jurors, especially when the posture of Dr. Campbell’s testimony left counsel unable to dispute the figure.
I would hold that when, as in this ease, an expert offers a statement that is represented as being a direct quote from a book, the testimony is admissible only if the source material is present in the court room and available for inspection by opposing counsel.
Even if the statistical testimony qualifies for treatment as a hearsay exception, I nevertheless feel that there was an inadequate foundation laid for its admission in this case. Because of the overwhelming impact on a jury of statistical evidence that indicates an almost insurmountably conclusive probability of an accurate identification, and because of the ever present danger that the presumptions on which such calculations are based might be flawed, evidence of mathematical probabilities should be admitted only if there is a thorough foundation articulated by the expert supporting the legitimacy of the conclusion reached. See People v. Collins, 68 Cal.2d 319, 66 Cal.Rptr. 497, 438 P.2d 33 (1968). McCormick on Evidence § 204 (2d Ed. 1972). To permit an expert to offer a probability figure without a complete explanation of how the number was calculated would not only intensify the mystery surrounding pronouncements of such huge probability figures but also, “foreclose(s) the possibility of an effective defense by an attorney apparently unschooled in mathematical refinements.” People v. Collins, 66 Cal.Rptr. at 502, 438 P.2d at 38. In this case, the defense attorney’s difficulty in attempting to defuse the impact of the large numbers was compounded by the fact that Dr. Campbell had not performed his own calculations and could not cite the source of the general formula. Because of his ignorance of not only the method by which the figure was calculated, but also the treatise where it could be verified or disputed, his testimony was essentially immune from the test of cross examination.
The science of comparing bite-marks begins with the assumption that any individual’s bite-mark is unique. In attempting to identify a bite-mark by comparing it with the known mark of an accused, the forensic orthodontologist selects several distinct features or characteristics of a bite-mark such as the individual shape of the teeth (as *262evidenced by the mark), the spacing between the teeth, and the size of the arch. The expert then conducts a methodical comparison of each aspect of the two bite-marks, determining whether there is similarity with respect to any or all of the features. As in fingerprint analysis, as the incidence of the finding of similarity among the “points of comparison” increases, so does the assurance that any overall identification is “positive”. See Warren and Harvey Dental Identification and Forensic Odontology (1976).
While Dr. Campbell’s testimony on the matter is of little assistance, it appears that the probability figure, “eight in one million” is reached by application of the so called “product rule” to the comparison technique described above. In simple form, the rule is that if two or more events are mutually independent, the probability of their co-occurrence is equal to the product of their individual probabilities. See McCormick on Evidence, § 204 (2nd Ed. 1972). In bite-mark analysis, the underlying events used as the basis for calculating a product are the individual probabilities that there will be similarity in two bite-marks with respect to any one of the isolated characteristics described above.
The California Supreme Court’s primary objection to the testimony offered in People v. Collins, supra, was that there was no empirical evidence offered to justify the probability figure assigned to each “event” used to calculate the figure “one in twelve million”. The difficulty with the testimony of this case is just as serious. There was no evidence offered to justify the statistical weight assigned to each identification factor. Moreover, the absence of an explanatory foundation disguised the fact that the eight in one million figure taken from the literature was completely misleading when applied to the comparison study actually performed in this case.
Assume, for ease of calculation, that the probability of finding similarity in two bite-marks with respect to each discrete aspect is one in four. Assuming the independence of each variable, the probability of finding similarity with respect to two features is one in sixteen; with respect to three features, one in sixty-four. It should be apparent that as the number of findings of similarity increases, the denominator of the probability fraction rises exponentially. Far more significant jumps occur, for instance, when the findings of similarity increase from seven to ten.
The problem with Dr. Campbell’s having utilized the figure “eight in one million” in this case is that while he was able to testify that that figure represents the product of the probabilities that there will be similarity in ten major points of comparison, he also testified that because of “inconsistency,” he did not employ all of the ten major factors in making his identification. It is clear that the discrepancy between the comparative assumptions underlying the figure announced by Dr. Campbell and the actual comparison study performed by him in this case render the eight in one million figure totally irrelevant. However, because of his unfamiliarity with the statistical weight assigned to each comparison factor, Dr. Campbell would have been completely unable to explain to the jury the degree to which his figure was exaggerated when applied to this pair of bite-marks.
As an illustration, assume that Dr. Campbell failed to consider three of the ten major factors in making his comparison. Assume further that the variables not considered are independent and that each has a statistical weight of one in four. It would seem then that considering only the remaining seven points of comparison, the probability of the bite-marks being identical would be reduced to below one in two thousand.3
When this failure of Dr. Campbell to perform his own calculations is compounded by the fact that the figure in the literature for a study based on all ten factors is eight in one hundred thousand, it is obvious that a proper application of the product rule *263would have yielded a substantially less imposing figure than eight in one million.
In conclusion this case highlights the numerous pitfalls that can be encountered by permitting probability evidence without a demonstration of the validity of the figure announced by the expert. I would hold that such testimony is admissible only if the witness is thoroughly familiar with the relevant probability formula and can justify the statistical weight assigned to each variable in that formula. I would further require that the expert be able to fully explain to the court the calculations he performed in arriving at his ultimate conclusion.

. Moreover, the applicability of even an eight in one hundred thousand figure to the defendant is dubious. Warren and Harvey are referring to the probability of a specific combination of distinctive tooth characteristics occurring in Scotland where “not more than sixty percent of the adult population over sixteen have some natural teeth”. Dr. Campbell never suggests that any of these same specific characteristics were present in the bite-marks that he studied.

. This figure has been rounded off, to facilitate calculations, from the actual 1977 population of Pima County which was 468,100. Valley National Bank of Arizona, Arizona Statistical Review, (33rd ed., 1977) at 8.

. This figure is reached by calculating the product of the hypothetical probabilities of the ex-eluded factors, and dividing the figure eight in one million by that product.