In dynamic video-recorded scenes where several people move around within the frame and from camera to camera it can be difficult to accurately track the movement of individuals. This makes it challenging for the trier of fact to understand what is happening generally and to differentiate the actions attributed to each individual. Motion tracking is a forensic video analysis technique that can be used to assist the trier of fact in comprehending and interpreting this type of video evidence with greater clarity. There have been a limited number of judicial rulings on the admissibility of motion tracking evidence, but a recent Supreme Court of Connecticut case represents the first time the highest court in a state has ruled upon this issue. This article discusses how motion tracking was used in this case and how the Court evaluated its admissibility.

Two earlier articles on this website are also helpful for contextualizing the issues in this case: Defence Challenges Motion Tracking by Forensic Video Analyst: Too Helpful Perhaps? and California Court of Appeal Rules Upon the Propriety of Forensic Video Analysis Techniques Utilized by Expert.

The Connecticut Case

In State v. Bruny, 342 Conn. 169, 269 A.3d 38 (2022), a decision of the Supreme Court of Connecticut, the Court was tasked with addressing several grounds of appeal stemming from convictions by a jury for murder and criminal possession of a firearm. I will address the issues that relate to the video evidence relied upon by the prosecution as part of their case.

First, the overall case facts. The defendant and several friends went to a nightclub and about forty-five minutes after their arrival, the victim and his friends arrived. One of the defendant’s friends threw a bottle at the victim’s group. Seconds later, a person walked up to the victim, put a gun to his head, and pulled the trigger. The victim fell to the floor and most of the patrons fled. The prosecution alleged that the defendant was the person who killed the victim. The nightclub had a multi-camera CCTV system that recorded the relevant events leading up to the murder, the murder itself, and the aftermath.

The Expert Evidence

One of the police officers who attended the scene reviewed the CCTV footage from the nightclub and exported the video files to a thumb drive. The video evidence was later sent to a forensic examiner (the “expert”) at the FBI. The expert examined the individual camera views in detail, adjusted brightness levels, clarified the images, and tracked the movement of various individuals, each of whom was identified with a visible alphanumeric code, as they moved within the frame and from camera to camera. For court presentation purposes, the expert prepared a fifty-two-minute video compilation. The presentation included video clips from different cameras and the motion tracking annotations. It also occasionally showed two camera views at once using a split screen and slow motion to focus on certain aspects of the movement from different perspectives. A spotlight effect was used to highlight portions of certain images. Using the court presentation, the expert described and demonstrated in detail how he confirmed the tracking of each designated person through the recorded events. The expert’s work was very helpful in understanding what happened within the nightclub. It is important to note that the expert never identified the defendant as the shooter, nor was he asked to do so. The expert spent hundreds of hours conducting the forensic video analysis.

The Trial Judge’s Ruling on Admissibility

The trial judge ruled that the expert’s evidence was properly categorized and admitted as expert evidence under Section 7-2 of the Connecticut Code of Evidence, which provides:

A witness qualified as an expert by knowledge, skill, experience, training, education or otherwise may testify in the form of an opinion or otherwise concerning scientific, technical or other specialized knowledge, if the testimony will assist the trier of fact in understanding the evidence or in determining a fact in issue.

The trial judge was satisfied that the expert possessed specialized knowledge, skill, experience, training, and education that was relevant to the issues before the court and that his knowledge was beyond that of the jury. Further, the trial judge was satisfied that the jury would benefit from the expert’s assistance. To avoid conflict with a prior Connecticut ruling, the judge required the expert to remove the alphanumeric labels over each person for several seconds before and after the shooting occurred to avoid an argument that the expert was identifying the shooter. Whether this perceived cautious step was necessary or whether it had the desired effect is questionable as the alphanumeric label did not operate in such a way as to identify anyone but rather to distinguish each person from the others in the dynamic events.

The Appeal to the Supreme Court

The defendant argued on appeal that the trial court abused its discretion by allowing the FBI expert to testify regarding the enhanced video that he created from the individual CCTV recordings and his tracking of the movement of certain individuals through the nightclub. His main argument was that the expert’s testimony invaded the province of the jury, meaning that the expert was doing the work that the jury should do unassisted.

In assessing the propriety of using motion tracking to parse out the movement of individuals in a crowded and dynamic scene, the Court relied in part on the California Court of Appeal decision in People v. Tran, discussed in the above cited article, which approved of the use of motion tracking and found it helpful for the trier of fact to understand dynamic movement. The Supreme Court noted that the expert had extensive experience in forensic video analysis and that he used motion tracking in the Boston Marathon case and the Pulse nightclub shooting in Florida for the same purposes as in the present case. The Court found that the nightclub video images were challenging for viewers in that there were several camera views, the lighting was low, the club was crowded, and there was considerable movement of people within the field of view. Further, individuals moved from camera to camera which made the job of tracking them through the events difficult. The Court noted that the extensive forensic work undertaken by the expert was beyond the ability of the average person to perform or understand. The Court found that the expert’s overall analysis, including the motion tracking, assisted the jury with their task and further, that because he was not asked to identify the shooter, his evidence did not invade the province of the jury. The prosecution was still required to independently prove the identity of the shooter observed on the video. As a result, the Court was satisfied that the trial judge correctly admitted the evidence of the expert at trial.

Commentary

One of the themes that I explore in my PhD work is that images rarely speak for themselves and often need interpretation by a person with personal or expert knowledge of image content. Part of developing visual literacy is for counsel and the court to know when expert assistance is required to fully understand the evidence. The goal should be to provide the trier of fact with the necessary interpretive assistance so that they can make informed findings of fact. Motion tracking is an example of an interpretive forensic process that can assist the trier of fact better understand dynamic events. As is often the case, when such evidence is tendered, opposing counsel argues that it is too helpful and that it does the work the jury is supposed to perform. Sometimes those arguments work (see for example Canadian Court Restricts Evidence of Forensic Video Analyst in Murder Trial) and sometimes they don’t work. However, provided the expert properly conducts the motion tracking work and explains it to the court, and counsel competently argues the point with supporting case law, it should be a rare case where motion tracking evidence is denied entry.

One final comment. The video compilation presented by the expert was entered as a demonstrative exhibit only whereas the individual nightclub videos were marked as full exhibits. I suggest that this was an erroneous approach. Demonstrative evidence has no independent evidential value. It adds little to the discourse and is merely used to explain other independently admissible evidence. I view the motion tracking evidence in this case as substantive evidence that would assist the jury in understanding the raw video evidence and something they should be able to rely upon in their determinations. As a result, it should have been tendered and admitted as a full exhibit.