In preparation for a Canadian homicide prosecution, a forensic video analyst performed several technical and analytical processes on video images that captured relevant events. The defence objected to most of the work performed by the analyst and in a pre-trial motion during which the analyst gave extensive testimony, the trial judge ruled on the admissibility of various components of the analyst’s proposed expert evidence. The purpose of this article is to outline the technical and analytical processes that were undertaken by the analyst, the arguments raised against it, and the court’s various rulings. Note that although these pre-trial rulings were made in 2021 (R. v. Khiar and Osman, 2021 ONSC 4677 (Ontario Superior Court of Justice)), there was a publication ban in effect until after the jury trial was conducted in 2022, hence the delay in publishing this article.

Image Clarification

The analyst isolated relevant video images and enlarged them so that areas of interest could be better visualized. He then applied a sharpening filter to make content edges more apparent and to restore the definition of the original image. He also stabilized the enlarged images and deinterlaced them to “smoothen” jagged linear areas. The analyst testified that applying these filters does not alter the original image but rather adds layers over it. Finally, the playback speed was reduced thereby allowing the viewer to better understand the event (e.g., counting muzzle flashes). On a second video clip which was much brighter than the first, the analyst cropped the image, adjusted the brightness and contrast, added a white balance filter to control excessive brightness and a sharpening filter to intensify and darken edge detail. Finally, he added a spotlight filter to highlight the area of interest.

In cross examination, the defence argued that the analyst was “enhancing” the video evidence and the analyst resisted that categorization by saying that he was “clarifying” the original images to make them more “comprehensible” to the viewer. In my view, this is merely a matter of semantics. Enhancement is not a pejorative word in the forensic video analysis realm. Whether enhancing or clarifying, the result is the same – it is easier to discern image details. Enhancement is not equated with manipulation, which would be more problematic. As will be discussed below, the trial judge ruled the image clarification evidence to be admissible.

Motion Tracking

The analyst was asked by investigators to track the movement of three central figures in a video recording. This was accomplished by superimposing a different coloured ellipsis over each person which then tracked with each person when movement occurred. In practice, this is a frequently used helpful method of tracking movement during dynamic events. In this case, the trial judge expressed concern as to the admissibility of the motion tracking video on the basis that the jury likely did not need this assistance to follow the movements of the individuals. Perhaps sensing a negative ruling, the Crown opted not to tender the motion tracking video. Midway through his ruling, the judge noted that he likely would have ruled it inadmissible had he been required to rule on the matter, making his comment obiter (not necessary for the ruling) and therefore not precedential. By the end of the ruling, the trial judge firmed up his opinion and expressly prohibited motion tracking. The value of motion tracking is dependent upon the nature of the video recording and this putative ruling is within the trial judge’s discretion.

Infrared Light Effects

The analyst explained the impact that infrared light can have on the appearance of image content, namely that it can change the colour and tone of items such as clothing, making the clothing look different in different lighting conditions when in fact it is the same clothing. This aspect of the analyst’s evidence was not challenged by the defence and was ruled admissible on the basis that it would be helpful to the jury to have this explanation.

Image Comparison

In relation to video evidence regarding a second homicide that was part of the same prosecution, the analyst was asked to compare the clothing worn by the defendant and two of his associates in video images recorded at one location with the clothing worn by the defendant and his associates in a separate video recording at a different location later in the evening. This aspect of the analyst’s evidence was the most controversial and there was extensive cross examination and judicial commentary on the topic. The trial judge expressed reservations about this proposed comparison evidence for two reasons. First, he was of the view that the jury did not require expert assistance and would be capable of conducting their own comparisons. Second, such evidence would have the effect of transforming the analyst into an identification witness. Regrettably and apparently because of resistance from the trial judge, the Crown elected not to lead any image comparison evidence and relegated the analyst to commenting on the appearance of the clothing under different lighting conditions without offering any comparison evidence.

In fairness to the Crown, one of the factors that influenced the trial judge’s view of the propriety of the proposed image comparison evidence was the fact that the analyst was instructed by homicide investigators to assume that the person of interest in both location videos was the same person. Respectfully, this was a red herring and was not a relevant consideration. Though the issue of bias was likely raised, that was not a significant concern in this case. Irrespective of what the analyst was asked to assume, the images remain the same. Any comparison conducted by the analyst would not be tainted by bias since the jury could view the clothing’s characteristics and make their own assessment. The trial judge was not required to issue a formal admissibility ruling but he certainly expressed his view that it was not admissible. Despite not being required to rule on this issue given the Crown’s withdrawal of the evidence, the trial judge nonetheless expressly prohibited any image comparison evidence. This too was obiter and does not create a precedent.

Admissibility of Expert Evidence

The Supreme Court of Canada in Mohan articulated four threshold criteria that must be met for expert evidence to be admissible. Those criteria are relevance, necessity, the absence of an exclusionary rule, and a properly qualified expert. In this case, relevance was easily established since the video recording captured key events in relation to the homicides. As to the issue of necessity, the defence argued that the jury did not need assistance in clarifying the video images as they could do that themselves in the jury room provided they were given the necessary software. [Yes, you read that correctly.] The trial judge ruled that the image clarifications were necessary for the jury to better discern details and assess the images more comprehensively. As to the novel idea of giving the jury the forensic software to do the forensic work themselves, the judge pointed out the folly of such a proposal. First, it implicitly acknowledges the need for such work, which is why the Crown sought to lead it. Second, it assumes that jurors can competently utilize forensic software and become forensic video analysts on the spot. Third, it would turn the jurors into secret investigators and fourth, it presumes that the jurors could somehow do a better job than the analyst. The work of the analyst was therefore found to be necessary to assist the jury in their fact finding. As to whether the analyst was properly qualified, the trial judge was satisfied that his extensive LEVA and other training and experience placed him the expert realm.

Interestingly, the trial judge was primarily focused on the issue of whether the forensic video analysis altered the original video such that it should be excluded. The evidence of the analyst was that his work did not alter the images but rather served to clarify them and make them more “comprehensible”, while remaining accurate renditions of the original images. Following a review of trial level decisions across Canada, the trial judge focused on the Alberta Court of Appeal decision on this issue (R. v. Bulldog (2015), 326 C.C.C. (3d) 385, at para. 26-37, wherein the Court noted that the appropriate test for the authentication of video evidence is one of “substantial accuracy” and that where an alteration enhances a video recording, its accuracy may be improved by such an alteration. The Court ruled that the proponent must establish that what is being presented is a substantially accurate and fair representation of what the video recording purports to show.

Using that test, the trial judge was satisfied that the clarifications performed by the analyst were substantially accurate and therefore admissible on that basis. He noted that the clarifications allowed the viewer to see more details that were visible in the original images. Further, the original media would be shown to the jury so that they have the benefit of seeing both versions. The trial judge also noted that the technology used by the analyst has been used in Europe and North America for several years and there was no evidence to suggest that it was controversial. The analyst’s work was also reproducible by an expert with similar tools and competence. Lastly, the analyst was a credible and reliable witness who explained his evidence in a manner that made it understandable. As a result, the evidence was authenticated and there was no legal basis to exclude it. Though his evidence would be lengthy in front of the jury, the trial judge noted that the analyst may prove to be the most important witness and it was important for the jury to have his assistance and expertise presented for their consideration.

Final Comments

Not surprisingly, the trial judge permitted expert evidence regarding image clarification and the impact of infrared light and lighting generally on the appearance of image content. Those are not particularly controversial topics. What is troubling is that he would not have permitted motion tracking or image comparison evidence, both of which can be of substantial benefit to a jury when assessing the meaning to be drawn from video images. It is equally troubling that the Crown withdrew this expert evidence from consideration. As a former Crown Prosecutor with over 30 years of experience, I can appreciate that sometimes the writing on the wall is very clear and that avoiding a negative ruling can be tactically wise. Equally, there is merit in having the judge issue a formal admissibility ruling on evidence under consideration and then having the option to appeal that ruling to the Court of Appeal in the event of an acquittal. That approach also carries risk as the Court of Appeal may agree with the trial judge thus creating new appellate law on the issues. The trial judge’s ruling does not comment on the Crown’s motivation for withdrawing the expert evidence other than to say it was wise to do so.