Opinion ID: 2222257
Heading Depth: 1
Heading Rank: 2

Heading: Admissibility of Random Match Probability Statistics

Text: In the initial appeal to this court, Roman Nose argued that the BCA should not have been allowed to testify using random match probability statistics, also known as the product rule, that there was a 1 in 63 trillion probability that a randomly selected person would have the same DNA profile as Roman Nose or Stuedemann. [3] We now address this issue. In Roman Nose's initial arguments to this court, he asserted that this court recognized potential sources of error in computing probability figures in State v. Bloom, 516 N.W.2d 159, 160-62 (Minn. 1994), but, nevertheless, upheld use of the interim ceiling method recommended by the National Research Council (NRC) because it is a conservative method of statistical calculation designed to favor the defendant. Because the DNA probability statistics were calculated under the product rule and not the interim ceiling method, Roman Nose argued that the DNA probability statistics should not be admissible. Roman Nose also argued against the use of the product rule based on findings by an outside consultant that there were disparities and significant linkage disequilibrium in the BCA's databases. In response, the state asserted that the interim ceiling method approved in Bloom was not used with the PCR-STR method of DNA testing because of technological advancements. Further, the state argued that the product rule had been recommended by the NRC in their updated report issued in 1996 for PCR-STR testing and it was, therefore, a proper means of presenting the probability of a random match. [4] As for the BCA's database, the state asserted that any departures from linkage equilibrium would have a relatively minor effect on the product rule. On remand, both parties presented additional testimony and evidence on the alternative probability statistics used in the presentation of DNA evidence. Based on this additional evidence, the district court made supplemental findings and conclusions on the presentation of DNA evidence. In its supplemental findings, the court concluded that for single source samples, the product rule was generally accepted in the forensic scientific community as producing results that are scientifically reliable as accurate. For mixtures, however, the court concluded that, except in limited cases, the results of DNA identity analysis should be presented using the Combined Probability of Exclusion (CPE) [5] or the Likelihood Ratio (LR) [6] calculation and not the product rule. In reaching these conclusions, the court did not state that it erred when it allowed the state to present DNA evidence using the product rule at trial. In this appeal, both parties have provided supplemental arguments on the statistics used in the presentation of DNA evidence based on the additional findings and conclusions made by the district court. On remand, it is the duty of the district court to execute the mandate of this court strictly according to its terms. Halverson v. Village of Deerwood, 322 N.W.2d 761, 766 (Minn.1982). The trial court has no power to alter, amend, or modify [this court's] mandate. Id. (citing Tankar Gas, Inc. v. Lumbermen's Mut. Cas. Co., 215 Minn. 265, 9 N.W.2d 754 (1943)). After our initial review, we remanded this case to the district court for a hearing on whether the PCR-STR method of testing DNA has gained general acceptance within the relevant scientific community, not on the statistics used to present DNA evidence. Roman Nose, 649 N.W.2d at 823. The district court, itself, acknowledged in its order that its supplemental findings and conclusions on the probability statistics are more relevant to the weight to be given PCR-STR analysis than to the general acceptance of such analysis and that some of the evidence received was beyond the scope of the hearing ordered. We hold that the DNA statistical testimony and additional DNA statistical evidence along with the district court's supplemental findings and conclusions relating thereto exceeded the scope of remand. Having reached this conclusion, we must then decide to what extent, if any, we consider the additional information presented on probability statistics in addressing Roman Nose's challenge to the use of the product rule. We have in the past refused to consider findings made by a district court that exceeded the scope of remand even if such findings were supported by the record. See Interstate Power Co., Inc. v. Nobles County Bd. of Comm'rs, 617 N.W.2d 566, 580 (Minn.2000) (concluding that additional reasons for denial of a conditional use permit (CUP) not raised in the initial proceedings could not be used to support denial of the CUP because they were beyond the scope of remand); Sefkow v. Sefkow, 427 N.W.2d 203, 213 (Minn.1988) (concluding that the district court erred in determining the custody of a sibling because it was beyond the scope of remand). Policy considerations further support this conclusion. If we were to consider additional evidence presented beyond the issue to be determined on remand, the parties might consider the remand proceedings to be a second bite at the apple and attempt to further litigate all issues in the case. Additionally, if the focus of the proceeding on remand is on a specific issue and one of the parties is allowed to introduce evidence on a second issue, the opposing parties may not be adequately prepared to address the second issue, and we may make conclusions based on incomplete information. We therefore conclude that the additional testimony and evidence presented on probability statistics at the hearing on remand will not be considered in resolving the question of whether the district court abused its discretion when it allowed DNA evidence based on the product rule. Accordingly, we will limit our review to the record as it was at the time of the original appeal to this court. The record reveals that the district court had the following information available to it at trial. Prior to 1994, this court had consistently limited the admissibility of statistical population frequency evidence. See State v. Joon Kyu Kim, 398 N.W.2d 544, 548 (Minn.1987); State v. Boyd, 331 N.W.2d 480, 483 (Minn.1983); State v. Carlson, 267 N.W.2d 170, 176 (Minn.1978). In Carlson, we held that the district court erred when it allowed expert testimony that there was a 1-in-800 chance that the pubic hairs found on the victim were not the defendant's and a 1-in-4,500 chance that the head hairs found clutched in the victim's hand were not the defendant's. 267 N.W.2d at 176. In Boyd, we held that testimony that none of the tests excluded the defendant was admissible, but that probability evidence of a 99.911 percent likelihood of paternity based on blood test results was inadmissible. We noted that: [T]here is a real danger that the jury will use the [statistical population frequency] evidence as a measure of the probability of the defendant's guilt or innocence and that the evidence will thereby undermine the presumption of innocence, erode the values served by the reasonable doubt standard, and dehumanize our system of justice. 331 N.W.2d at 483. In Kim, the state attempted to introduce expert testimony that the semen found in the victim's body and on a bed sheet was consistent with Kim's blood type and that 96.4 percent of the males in the Twin Cities could be excluded as possible sources of the semen found on the bed sheet. 398 N.W.2d at 547. In that case, we reasoned that: As in Boyd, the expert called by the state in this case should not be permitted to express an opinion as to the probability that the semen is Kim's and should not be permitted to get around this by expressing the opinion in terms of the percentage of men in the general population with the same frequency of combinations of blood types. The expert should be permitted to testify, however, as to the basic theory underlying blood testing, to testify that not one of the individual tests excluded Kim as a source of the semen and to give the percentage of people in the general population with each of the individual blood types, and to express an opinion that scientific evidence is consistent with Kim having been the source of the semen. Id. at 549 (emphasis in original). In 1994, we created a DNA exception to the rule against admission of statistical probability evidence in criminal prosecutions to prove identity in Bloom. 516 N.W.2d at 160. In creating this new DNA exception, we noted that the justification for the exception was the National Research Council's [NRC's] recent adoption of the conservative `interim ceiling method' for computation of the probability that a randomly selected person would have the same DNA profile as that of a sample of bodily fluids found at a crime scene. Id. Under the DNA exception, we held that if the evidentiary foundation was sufficient, a properly qualified expert could give an opinion as to the random match probability using the NRC's [interim ceiling method] approach and not be limited to stating that the DNA test results are merely consistent with the defendant being the source of the evidence. Id. at 167-68. We further held, however, that the expert should not be allowed to testify that a particular profile is unique, state that the defendant is the source to the exclusion of all others, or express an opinion as to the strength of the evidence. Id. at 168. Subsequent to Bloom, the NRC re-examined the use of the ceiling principles, which include the interim ceiling method, in calculating the product rule in its 1996 report. National Research Council, The Evaluation of Forensic DNA Evidence 156-159 (1996). The NRC concluded that the ceiling principles were not applicable to PCR-based systems. Id. at 158. The NRC further determined that the procedures recommended in Chapter 4 of the report encompass suitable degrees of conservatism and that with such procedures available, the interim ceiling principle was no longer necessary. Id. at 159. One of the recommendations made by the NRC in Chapter 4 was that [i]n general, the calculation of a profile frequency should be made with the product rule. [7] Id. at 122. In addition to adopting the adjustments recommended by the NRC in its 1996 report, the BCA also adjusted its use of the product rule in accordance with recommendations made by the outside consultant who found departures from linkage equilibrium in the BCA's database. Given our holding in Bloom, the new recommendations from the NRC, and the BCA's use of an outside consultant to ensure accurate reporting of information, the district court could have reasonably concluded at the time of trial that the use of the product rule to report DNA evidence was appropriate. We recognize that use of the product rule to present DNA evidence results in extremely large numbers and because of the large numbers, the concern that we articulated in Boyd is still therethat the jury will use the probability evidence as a measure of the probability of the defendant's guilt or innocence, thereby undermining the presumption of innocence. We further cautioned district courts in State v. Kromah to be mindful of the potential impact such numbers may have on jurors and noted that courts should take steps to ensure that the presentation of the statistical evidence is not unfairly prejudicial or misleading. 657 N.W.2d 564, 567 n. 4 (Minn.2003). While recognizing the potential impact the large numbers generated by use of the product rule may have on jurors, we also recognize that the scientific community has approved the use of the product rule for analysis of results obtained from the PCR-STR method of testing DNA, and we have continually looked to the scientific community for guidance in resolving difficult issues such as these. Further, the record indicates that Schoenbauer's testimony that the probability of a match was 1 in 63 trillion was made as part of her overall presentation of DNA results and was not highlighted or emphasized above her other conclusions, thereby increasing the likelihood that jurors would place undue weight on the statistical results. We therefore conclude that the DNA probability statistics were not presented in a prejudicial or misleading manner and that the district court did not abuse its discretion in admitting DNA probability statistics using the product rule in this case. Because of the danger that juries will misunderstand, place undue weight on, or make inappropriate inferences from statistical probability testimony, Roman Nose contends that if we conclude that the statistical probability testimony is admissible, the district court should have provided cautionary jury instructions such as those proposed in Justice Page's concurring opinion in Bloom. [8] The district court concluded that such cautionary jury instructions were not necessary in this case. The court believed that such an instruction would highlight the importance of DNA opinion evidence over other scientific opinion evidence such as the medical examiner's analysis of the condition of the victim's body and the BCA's fingerprint analysis. Furthermore, the court believed an instruction on expert testimony sufficiently covered the topic. [9] While courts may disagree whether cautionary jury instructions are required when DNA evidence is presented, we cannot say the district court abused its discretion in failing to provide cautionary jury instructions in this case. Although we have not considered the additional evidence on probability statistics presented at the hearing because it exceeded the scope of the remand, we note that consideration of that evidence would not have produced a different result. The additional evidence supports the conclusion that use of the product rule is appropriate when applied to a known single source sample, and Roman Nose concedes the validity of that conclusion in his brief by acknowledging that a random match probability statistic [product rule] is scientifically acceptable when applied to a known single source sample   . Of the eight items on which DNA testing was performed, six items involved single-source samples and two items involved mixtures in which a predominant DNA profile could be identified. While the use of the product rule in mixtures where a predominant contributor has been identified may be subject to some debate, [10] we note that the DNA results from the six single-source samples are sufficient to implicate Roman Nose in Stuedemann's killing. Admissibility of Testimony that BCA Saves Half of the Sample for Defense Roman Nose next contends that the district court erred when it allowed Schoenbauer to testify on redirect examination that it is BCA policy to save half of every DNA sample so that a defense expert can perform his or her own testing on the DNA sample. [11] In support of his argument, Roman Nose points to our rulings in State v. Porter, 526 N.W.2d 359, 365 (Minn.1995), and State v. Jobe, 486 N.W.2d 407, 418 (Minn.1992), in which we concluded that a prosecutor may not comment on a defendant's failure to call witnesses or to contradict testimony because such comments might lead the jury to believe that the defendant has a duty to call witnesses or bears some burden of proof. In response, the state contends that we permitted precisely the same kind of question in Jobe. In Jobe, after defense counsel suggested that there would not be sufficient blood remaining for retesting after the state concluded its testing, the prosecutor asked the state's blood expert if there would be sufficient blood to test. 486 N.W.2d at 418. The prosecutor also asked the defense's DNA expert, who was critical of the FBI's DNA testing procedures, whether he could do the same testing procedure in his laboratory if he had samples. Id. We concluded that the challenged questions were not as explicit as those comments that we held improper in State v. Caron, 300 Minn. 123, 126, 218 N.W.2d 197, 199 (1974), [12] nor did they make the slightest suggestion that appellant was obligated to pursue independent testing, and consequently, the questions did not impermissibly shift the burden of proof. Jobe, 486 N.W.2d at 418. Roman Nose contends that the circumstances in Jobe are different from those in this case. Roman Nose asserts that his counsel never suggested that he could not conduct his own DNA testing as the prosecutor did in Jobe, 486 N.W.2d at 418, and therefore, there could be only two possible reasons for the prosecutor's questionthe prosecutor must have either intended to imply that Roman Nose had some obligation to independently conduct DNA testing or that the jury could draw an adverse inference from his failure to do his own testing, both of which are improper inferences. The record indicates that in the cross-examination of Schoenbauer, defense counsel questioned Schoenbauer about BCA's policy for assigning forensic scientists to a case and determining which samples of those collected would be tested for DNA. Then, seeming to challenge the thoroughness and competency of Schoenbauer's DNA testing, defense counsel questioned Schoenbauer about samples taken at the crime scene on which DNA testing was not performed. [13] On redirect examination, the prosecutor then asked Schoenbauer about BCA's policy of preserving part of the sample so that others, including the defense, could perform retesting on the samples tested by the BCA. The record, therefore, indicates that the prosecutor's question was at least in part a response to Roman Nose's argument that the state's evidence was insufficient because the BCA failed to test all of the samples taken from the crime scene. While we are concerned about the prosecutor's question regarding the defense ability to retest the sample, the district court could have concluded that the prosecutor's question was in response to Roman Nose's attack on the adequacy of the BCA's DNA testing and not intended to suggest that Roman Nose should have conducted his own testing. We cannot say that the court abused its discretion in allowing the prosecutor's question. The prosecutor's question did not impermissibly shift the burden of proof.