Opinion ID: 1878549
Heading Depth: 1
Heading Rank: 3

Heading: Cross-Examination of the DNA Expert

Text: Tyson argues that the trial court committed reversible error when it denied him what he characterizes as the right to fully cross-examine the prosecution's expert witness on DNA evidence. Tyson contends he should have been able to cross-examine the DNA expert regarding the possible effects of genetic subgroups in Alabama on the reliability of DNA statistics. In regard to a defendant's claim that he was denied his right of cross-examination, this Court has stated: [W]e note that a criminal defendant has the right to a thorough and sifting cross-examination, but that right is not absolute. The latitude and extent of cross-examination are matters within the sound discretion of the trial court, and in the absence of abuse, that discretion is not reversible on appeal. Ex parte Pope, 562 So.2d 131, 134 (Ala. 1989), cert. denied, 498 U.S. 841, 111 S.Ct. 118, 112 L.Ed.2d 87 (1990). We conclude, however, that Tyson has not shown that the trial court abused its discretion by refusing to allow him to cross-examine the DNA expert as he wanted to do. Tyson argues that the trial court erred in refusing to allow the following line of questioning to continue: Q. [By Tyson's counsel] Now, you mentioned 10 percent. If we could just take this example. Let's say that y'all were doing a survey in Europe, and let's say that you found that in doing your survey in Europe, you foundI've got blond written up here. Let's say one in ten people in Europe had blond hair, and let's say that in the survey of all of Europe you found that one in ten people had blue eyes. And in continuing on in your survey, you found that one in ten people in your survey of all of Europe had fair skin, okay? Now, in the multiplication rule, correct me if I'm wrong, would you not be multiplying these 10's on the bottom so that it would be 10 times 10 times 10 to get one in a thousand people in Europe would have blond hair, blue eyes and fair skin? A. That's true. That's the way it's done. Q. That would apply over all of Europe, correct? . . . . A. Whatever your number of ten came from, yes. Q. Now, if you were to take this multiplication of the product rule that you have come up with, this one in a thousand and you were to apply it and say in the Nordic region of Norway or Sweden, you would still be saying to expect to find one out of a thousand people in that area of Europe would have blond hair, blue eyes and fair skin, correct? [The prosecutor]: I object to that, that being THE COURT: Sustained.... In sustaining the objection, the trial court stated: The witness was asked to assume three different traits that are quite typical of Nordic populations. The witness was then asked, in my judgment deliberately, the extremely misleading question that that would lead to the conclusion that one out of a thousand persons in that population would have that characteristic. Now, that leads us into a realm of theoretical argument that is inappropriate to the trial of the case. That would make the cross-examination irrelevant and not to mention improper because it asks an expert witness to make assumptions that are not based on facts that are available in this case, and it would have presented to the jury the appearance that the witness who was askinganswering the question correctly based on a statistical analysis but had been led into that by askingby being asked false assumptions.... . . . . The problem is that this is not an academic environment, and what you did was not merely leading nor was it testing his knowledge. It wouldwhether you intended it or not, it had a strong tendency to create a misimpression in the eyes of the jury, and you almost had him expressingappearing to express the opinion that one in a thousand persons in a Nordic country had blond hair, blue eyes, and a fair complexion. And that was misleading because it was based on the assumption that you injected to start with. We agree with the trial court that the line of questioning and the tactics employed by Tyson's counsel were irrelevant and could have misled the jury. Furthermore, the DNA expert had previously testified during cross-examination as follows: That has been statistically proven that there is no subgrouping within the State of Alabama. What that means isa way to describe that would be a lot of American Indians, for example, let's say up in Alaska, very small community, a lot of them mate and marry one another. So, a lot of the same traits that they have stay within that very small pool because those people never go to Tuskegee, Alabama and mate, for example. So, that's what's called a very small subgroup. However, in Alabama the traits that we see within the black and the white population exhibit no subgrouping. And that's been shown statistically, as well as the fact that even to account for the possibility of subgrouping, we impose minimum numbers or frequencies to be even more conservative and account for that room [sic] of possibility. Tyson's counsel had already questioned the DNA expert regarding genetic subgroups and the possible effect such subgroups would have on statistical analyses of the population of Alabama. The witness gave a very thorough explanation regarding the effect of genetic subgroups in Alabama. Therefore, the trial court did not abuse its discretion when it denied Tyson the privilege of repeating such questioning in a manner likely to mislead the jury.