Aaron Evans faced charges of kidnapping and sexual assault for breaking into his ex-girlfriend's apartment and sexually assaulting her fifteen-year-old daughter. The prosecution relied on DNA samples extracted from physical evidence taken from the apartment and from the victim. As trial began, Evans's attorney, Michael Backes, requested that their expert witness be exempted from the court's order sequestrating all witnesses.
Backes wanted Dr. Alan Friedman, a listed expert defense witness, to sit at counsel table to assist in cross-examining the state's DNA witnesses. Backes argued that he needed the assistance because DNA is a complex matter that he found somewhat confusing. The state objected, saying it would frustrate the purpose of the sequestration order. The court refused Backes's request. Backes never raised the issue again, and he did not call Dr. Friedman as a witness. The jury convicted Evans.
An Essential Burden
Evans appealed. He argued that the trial court erroneously exercised its discretion in not allowing Dr. Friedman to assist Backes. Evans argued that Dr. Friedman could have heard the state's witnesses, viewed the actual evidence, and suggested ways to effectively cross-examine those witnesses.
The Wisconsin Court of Appeals reviewed Wisconsin Statute Section 906.15, which governs witness exclusion. The purpose of sequestration is to assure a fair trial by preventing witnesses from shaping their testimony based on the testimony of other witnesses.
While sequestering a witness is within the discretion of the trial court, the statute does not permit exclusion of a witness shown to be essential to the presentation of the party's case. But the burden of showing that the witness is essential is on the party seeking the exemption.
A showing that the witness's presence would be merely helpful or desirable is not enough. The party must show that the witness has such specialized expertise or intimate knowledge of the facts that counsel could not effectively function without the presence and aid of the witness. Oliver B. Cannon & Son, Inc. v. Fidelity & Cas, Co., 519 F.Supp. 668, 678 (D.Del. 1981).
Helpful, but Not Essential
Here Backes's statements in support of his request were broad and unparticularized. Backes showed Dr. Friedman's presence would be helpful, but not so essential that Backes could not effectively function with Dr. Friedman in the hallway rather than sitting next to him in the courtroom.
The Court of Appeals held that, on this record, the trial court did not abuse its discretion in denying Evans's request to exempt Dr. Friedman from the sequestration order. Judgment affirmed.
 | Paul Goldstein, Ph.D. Professor of Genetics and Toxicology University of Texas |
Goldstein: The use of an expert in court demands that the individual selected is qualified as an “expert.” Otherwise, such a person would have no “opinion,” especially one which must be based on scientific criteria and which has undergone peer review in the scientific community. In the case of Wisconsin v. Aaron Evans, one of the main components centers on the admissibility of the “expert” for the defense. The fact that the expert was never taken through voir dire to establish his/her credentials resulted in the refusal of the court to permit this individual to listen to the testimony of the DPS Lab technician when the DNA data was presented to the jury. From this, we learn that it is essential to prove to the court that a DNA expert is even needed, and to show the court that his/her opinions, learning, and elucidation of the facts are essential in the interpretation of the source of the DNA.
Can a layman understand the complexities of the production of the DNA data, whether the data is scientifically valid, and the interpretation of the data in the specific case? Absolutely not. In the above case, the defense attorney states that he needed the expert's help because DNA evidence was “a complex matter” which he found “somewhat confusing.” These are not grounds for the need of an expert. The attorney should have been more explicit: “I need an expert in DNA analysis who can determine if the DNA data was produced and interpreted following accepted scientific standards.” If he/she had been that explicit, the court's opinion that the “[o]ne seeking relief from a sequestration order bears the burden of showing that the person sought to be exempted from the order is ‘essential'; a showing that the person's presence would be merely helpful or desirable is not enough” may have changed in favor of the defense.
Why a DNA Expert Is Needed at Trial
The techniques used for DNA analysis have advanced almost as rapidly as our knowledge of gene sequences. In a few short years, judges and attorneys, DNA experts and technicians, have had to learn the details and applicability of Restriction Fragment Length Polymorphisms (RFLP), DQ-alpha, and Short Tandem Repeats (STR). Today, forensic labs are primarily using the STR technique to distinguish between the DNA from two or more individuals. However, they are woefully behind in their abilities to do so, since the crime labs use only tetranucleotide repeats (4 nucleotides) versus pentanucleotide repeats (which is at least 20% more accurate). In addition, with new DNA techniques that are already available, and with those in development, the “state of the art” in forensic labs is actually years behind. Thus, a qualified DNA expert is the only person who can interpret the data, and offer an “opinion.”
The DNA expert first has to determine if the forensic DNA Lab is accredited to do these specific tests, and if the technicians are certified. Did the DNA Lab use state of the art techniques that try to more precisely identify individuals? What criteria were used in determining the origin of DNA data from mixtures, or from a crime scene? When the DNA from the epithelial cell fraction (female portion) of the stain was compared to the possible donor (female) . . . was there a match? There had better be, because that serves as a primary internal control that the test was performed correctly! For those labs that use STR analysis, it is critical to establish the parameters used by the technician in defining the presence or absence of absorption peaks (which correlate with the DNA). The software used in the lab permits the technician to set guidelines that can eliminate alleles from the data. This is especially true for any allele that does not precisely fit into the known database. We call these alleles “variants” and hundreds are added to the database every month. If there are so many variants, how can you tell if it is specifically this variant, the one from your client, that exonerates that individual?
To summarize, Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993), demands that the highest quality of scientific evidence be used in the court. The presentation of such evidence is enhanced when a distinguished expert (Full Professor, member of the appropriate professional society, peer reviewed publications, grant support from national agencies, awards, etc.) is called upon to relate those principles to the specific case.
