In an earlier post entitled “Becoming Qualified as an Expert Witness for the First Time” I set out the four key requirements that must be met in order for expert evidence to be admissible. The fourth such requirement is that the proposed expert must have the necessary qualifications for the tendered field of expertise. That gives rise to the issue of what are the necessary qualifications?
It can be difficult to know when someone has amassed a sufficient amount of knowledge, skill, experience, training and education such that they can be tendered before the court as an expert witness. Having led expert evidence many hundreds of times and having qualified many experts for the first time in their career, I know from experience when someone has crossed the expert witness threshold but it is important to look at this topic more objectively.
When I teach my Courtroom Testimony for Expert Witnesses course in Canada and the United States, I use the example of a ride at an amusement park to make this point. These rides have a marker which indicates the minimum height required in order to go on the ride. Similarly, expert witnesses have to be sufficiently qualified in order to go on the “Expert Witness Ride.” And what a ride it can be! Some rides are smooth, short and pleasant. Others are challenging, long and decidedly unpleasant, typically as a result of cross examination.
Simply defined, an expert witness must know more about the specific topic than the trier of fact and must be able to assist the trier of fact in understanding that aspect of the case. This expertise must come from a combination of knowledge, skill, experience, training and education. The attorney must undertake a qualitative analysis of the expert’s qualifications in order to determine if the expert is sufficiently qualified to be tendered in court. In some areas of expertise such as engineering, medicine, psychiatry, dentistry, etc. there are clear minimum professional standards. In other areas of expertise, there may not be a clear minimum standard to meet and so the qualitative analysis of what the expert brings to the table is critical. The correct balance of attributes is required.
Attorneys must be satisfied that the proposed expert has the necessary qualifications to be tendered before the court as an expert witness. The trial judge then acts as the gatekeeper to ensure that only properly qualified experts are permitted to testify. In a later post, I will write more about this important gatekeeping function. It is critical that only properly qualified experts be allowed to testify in court. The admission of unqualified experts impacts upon the court’s ability to reach a proper conclusion in a case. Unfortunately, not all questionable experts are weeded out but in the following case examples from the field of forensic video analysis, we can see the gatekeeping function in action.
In Dunlap v. Hood, 2009 WL 362292 (2009, United States District Court, N.D. Texas, Dallas Division), a “certified forensic analyst” proposed to perform an “elemental analysis” of jailhouse surveillance video for the purpose of determining the number of officers that were involved in removing the plaintiff from a jail cell. The Court ruled as follows regarding the admissibility of the proposed expert evidence at page 2:
Based on his “elemental analysis” of the surveillance video, [expert] concludes that at least two officers participated in extracting plaintiff from the holding cell. However, [expert] reached that conclusion just by looking at the images taken from the surveillance video, unaided by any specialized knowledge or experience. Because [expert] is no better suited than the jury to interpret the contents of the video, his supplemental opinion is not the proper subject of video testimony.
This illustrates the need to actually bring some expertise to the table in order to be of assistance to the trier of fact.
This is further exemplified in Lee v. Andersen and the City of Minneapolis, 616 F.3d 803 (2010, United States Court of Appeals, Eighth Circuit). In this case, trustees for the heirs of Lee, who was shot and killed by a police officer, brought an action against the officer and the city alleging excessive use of force and state claims. In a pre-trial motion, Andersen and the city moved to exclude proposed expert testimony regarding whether Lee had a gun in his hand at the time he was shot. The trustees sought to call a video expert who had increased the contrast of the video images and clarified some of the relevant images. It was the expert’s opinion that Lee did not have a gun or any other object in his hand during the moments before the shooting. At his deposition, when asked what methods and principles he used to interpret the images, the expert replied “simple observation.” The trial judge granted the motion to exclude the proposed expert evidence on the basis that the jury did not need assistance in determining whether they could see a gun or any other object in Lee’s hand and that in any event, the expert did not employ any technique or utilize any specialized skill that was unavailable to the jury.
On appeal, the trustees argued that the trial judge erred in excluding the expert testimony regarding whether Lee had a gun or any other object in his hand. The Court of Appeals noted that Federal Rule of Evidence 702 permits a qualified expert to give opinion testimony if the expert’s specialized knowledge would allow the jury to better understand the evidence or decide a fact in issue. However, if the subject matter is within the jury’s knowledge or experience, the expert testimony is subject to exclusion because it does not meet the helpfulness criterion of Rule 702. Opinions that “merely tell the jury what result to reach” are not admissible.
State of California v. Hernandez, 2017 WL 2547316 (California Court of Appeal), is an instructive case. In this murder trial, the trial judge excluded the evidence of a defense video expert on the basis that the proffered evidence was based upon a novel scientific technique that was not reliable and therefore impermissible under Kelly and Frye. The expert purported to conduct a facial comparison analysis between known photos of the defendant and photos of the shooter. The expert claimed to use Euclidean geometry (which is based on axioms and theorems that allow generalizations from known facts), a technique he acknowledged other people did not use. He also used “Michelangelo theory” (his own technique of removing portions of a distorted digital image to reveal the true features of the person shown) as well as an unnamed and unexplained third technique utilized by him for looking at poor images. He opined that his margin of error was 5-8% and acknowledged that his approach was unique and not used by other experts. Further, the expert had no university training in these techniques, no image analysis certification and his work was not peer reviewed.
The Court of Appeal noted at pages 7-8 that:
The goal of the trial court gatekeeping is simply to exclude ‘clearly invalid and unreliable’ expert opinion. In short, the gatekeeper’s role ‘is to make certain that an expert, whether basing testimony upon professional studies or personal experience, employs in the courtroom the same level of intellectual rigor that characterizes the practice of an expert in the relevant field.’
The Court concluded that the trial judge was correct in excluding this evidence. The expert’s theories were new to science and law and it was not established that his theories had gained general acceptance in the relevant scientific community or that they were reliable.
At least in the above cases, the proposed expert was not allowed to testify before the trier of fact, though not for lack of trying on the part of the tendering attorney. It is more troubling when someone who should not have been permitted to testify owing to lack of proper forensic qualifications gives evidence. State of Iowa v. Pollard, 2007 WL 2408114 (Iowa District Ct.), illustrates this danger. The defendant was charged with first degree murder arising out of the hit and run death of a woman in a commercial parking lot. The State alleged that the defendant was driving his truck in the darkened parking lot when he struck and killed the victim. Key evidence in the case was surveillance video from three different stores that captured portions of the event. The State’s expert compiled a DVD with sequential clips from approximately 20 surveillance cameras that appeared to capture relevant images. The expert was not a forensic video analyst nor did he have any training in this field of expertise. The expert modified the compilation digital video evidence by speeding up portions of the video so as to make it look more likely that the truck shown prior to the hit and run was also the truck that struck the victim. The stated reason for speeding up this portion of the video was to make the images smoother. The actual end result was to make the video evidence more compelling than it really was by showing an inaccurate account.
An expert who analyzed the video evidence for the defendant determined that the State’s expert had intentionally modified the speed of the compilation video thereby giving a false impression as to what actually occurred. Further, it was shown that the methods used to convert the original video to DVD format removed detail, added digital artifacts and resulted in an incorrect aspect ratio. As a result the compilation DVD was not accurate as it was created without proper regard for the requisite forensic video methodology.
In analyzing the State’s video evidence and the evidence presented by the defendant’s expert, the Court noted that the State is obliged to show that the compilation DVD evidence is authentic, that is, that the video evidence is an accurate representation of the event recorded. Pursuant to the “silent witness” theory of video admissibility, there must be testimony from a witness capable of establishing the integrity, authenticity and competency of the video evidence. The Court concluded that the probative value of the altered portion of the video evidence was substantially outweighed by the danger of unfair prejudice. This ruling was based on the fact that the altered version of the video made it seem more likely that the truck shown earlier was also the same truck that struck the victim, a conclusion that could not fairly be reached from the unaltered video. The Court ruled that the altered portion of the video was inadmissible as a result but that that the other concerns raised by the defendant’s expert were issues that should be considered by the trier of fact and were questions of weight, not admissibility.
These cases illustrate that unqualified individuals are sometimes tendered before the court as experts and while we count on the court’s gatekeeping function to weed out such people, that does not always happen. Expert witnesses must actually be experts and must possess the necessary knowledge, skill, experience, training and education in order to assist in the search for the truth. Experts must also possess the necessary forensic mindset to truly be of assistance.