In Canada and the United States, courts rarely limit the ability of a qualified forensic video analyst to provide image comparison opinions. Conversely, in the United Kingdom, the Forensic Science Regulator has placed significant restrictions on the use of evaluative opinions. For more on the UK situation, refer to the article on this website entitled “Recommendations for Expert Image Comparison Evidence in the United Kingdom in Light of the FSR Regulatory Notice Image Enhancement and Image Comparison: Provision of Opinion.” Interestingly, a 2020 Canadian case has effectively followed the restrictive UK approach without specifically referring to it. 

R. v. Spezzano, 2020 CarswellQue 9308, (Quebec Superior Court), was a murder prosecution. As part of the prosecution’s case, a forensic video analyst was asked to undertake a comparison between questioned video images of a vehicle on a roadway and known images of the defendant’s vehicle. A voir dire was held to determine whether the analyst should be restricted in the opinion evidence sought to be given at trial. 

The Comparison Evidence

The analyst had questioned images of the vehicle on the roadway obtained from a nearby business’s CCTV system. A reenactment was also conducted using the defendant’s vehicle along the same roadway using the same CCTV system in similar conditions. Finally, the analyst was provided with images of the defendant’s vehicle. Following his comparative work, the analyst concluded that the vehicles shared several class characteristics (sedans, mid-tone grey, horizontal ridge line on lower portion of door, and similar headlights and taillights). Further evidence was given regarding the operability features of the lights and turn signals. No limited class characteristics were noted. The analyst was neither able to exclude the vehicles as being different or conclude they were the same. The strongest opinion reached was that the questioned vehicle was likely the same make and model as the known vehicle. 

The analyst was cross examined on the standards set out by the Scientific Working Group on Digital Evidence (SWGDE) and in particular, the following:

Before conducting image comparisons, individuals should have expertise in imaging science, knowledge of the objects being compared, and an understanding of the comparison methodology. […] Object knowledge is necessary to understand the significance of the features. Such knowledge may be developed in response to the needs of a specific case. For instance, a comparison involving an item of clothing may require research into the clothing manufacturing process. Understanding the comparison methodology is necessary to assess the utility of the features for comparison leading to conclusion. This combination of expertise may require both formal training and practical experience (e.g. on-the-job) among multiple disciplines, or it may require the involvement of multiple individuals with a variety of expertise.

The analyst testified that he complied with the SWGDE standards and that he had the requisite object specific knowledge. It was his view that general vehicle knowledge was sufficient and that specific knowledge about Mercedes (the vehicle in question) was not required. He further noted that SWGDE set out recommendations and guidelines that were not binding. 

The defence argued that forensic video analysis is a novel science, that showing questioned and known images side by side was overly suggestive, that the analyst was biased because the question he was asked to answer was whether the vehicles were the same, and that the reenactment would create “an extra witness for the state” and would therefore be unfair. For these reasons, the defence argued that the analyst’s evidence should be excluded. The Court rejected all these arguments (they had no merit) but restricted the analyst’s evidence for other reasons.

The Ruling 

The Court found that the reenactment evidence was not overly prejudicial and was therefore admissible. The Court further found that the analyst was a qualified expert and that his evidence was necessary. However, the Court ruled that the class characteristics pointed out by the analyst were within the knowledge of the jury and that his opinion on those matters was therefore unnecessary. Evidence on the technical aspects of the video (artifacts, the impact of vehicle speed and environmental conditions on light, and the impact of daytime and nighttime camera mode on the images) was admissible as that would be of assistance to the jury. Thus, the analyst was permitted to comment on the technical aspects of the images but was not permitted to offer a comparative opinion on the vehicles. Considering the restrictions placed on the analyst’s evidence, the Court did not need to address the issue of whether forensic video comparison evidence is a novel science. 

In summary, the Court restricted the analyst’s opinion evidence as follows:

• Commentary on technical aspects of the images is permitted but not when the questioned and known images are shown side by side because that would invite image comparison by the analyst.
• The analyst cannot show the questioned and known images side by side and offer comparison commentary. 
• Presenting single images in a manner or sequence which implicitly invites comparison by the analyst is not permitted. 
• No graphics are permitted. 
• No evidence as to the operability of the vehicle’s lights is permitted as the analyst is not a vehicle expert. 

Analysis of Court’s Ruling

The Court’s ruling in this case stands in opposition to most image comparison cases in Canada and the United States, cited in other articles on this website. The restrictions imposed are generally overly cautious and are dismissive of the value of image comparison evidence. The Court was however correct to prohibit the analyst from offering evidence on the operability of Mercedes lights as that was beyond his expertise. That evidence, if important, should be presented by a vehicle expert.  

It is my view that the trial judge was in error in restricting the ability of the analyst to provide comparison evidence regarding the vehicle images. Most case law supports the admissibility of the evidence tendered in this case. That does not mean that if this ruling had been appealed, the Court of Appeal would have necessarily decided otherwise. Trial judges are given significant deference by appellate courts in evidential rulings and are only overruled when clear legal error has been shown. As a matter of interest, this case was a retrial. During the first trial, heard by a different judge, the same issues were raised regarding the image comparison evidence and the trial judge admitted all the analyst’s evidence. The second judge obviously disagreed with that approach. 

Even though this ruling stands against almost all image comparison rulings in North America, it creates another argument to be used by opposing counsel in seeking to restrict image comparison evidence. Counsel must be armed with all relevant case law when seeking to admit this type of expert evidence and be able to distinguish the Spezzano ruling as being wrongly decided, or at least an outlier.