Slow Motion Video: New Jersey Speaks

April 16, 2024

Slow the video down

It moves too fast

But watch out it makes intent really last

Feelin’ groovy

(with apologies to Simon and Garfunkle)

The proliferation of video evidence- body cameras, store security footage, ring cameras, and the ubiquitous hand-held cellphone – can’t be questioned.  The use of video ranges from the high-profile cases, all too often involving police violence on civilians, to drunk driving and shoplifting cases.  As of 2018, the number of surveillance cameras in the U.S. was estimated at 30 million, with roughly 4 billion hours of footage shot per week. Yael Granot, et al., In the Eyes of the Law: Perception Versus Reality in Appraisals of Video Evidence, 24 Psych., Pub. Pol’y & L. 93, 94 (2018)

With its increased availability comes the matter of how it is displayed in the courtroom.  One recurring method, and one of concern, is to play the video in real time and then replay it in slow motion.

What’s the concern?  The answer may depend on the context of the case.  If the issue is one of identification, slowing down a video might permit juror attention to details (presuming that the slower speed does not somehow distort or exaggerate features).  But when the issue is one of intent, slowing things down makes them appear more deliberate than at full/normal speed.

There is solid research substantiating this.  A 2016 study in PNAS – Proceedings of the National Academy of Sciences – explained it this way:

what you can see only in the slower version is more time, or, more specifically, an actor who seems to have had more time to form and act on an intention. Two features of human judgment suggest that impressions of the duration over which real-time events unfolded are likely to be affected by the speed of video replay. First, duration estimations vary across people, situations, level of distraction, and estimation procedures, indicating that the mind’s timing mechanisms are susceptible to the influence of incidental factors. Second, even when people are aware that an incidental factor (e.g., slow motion) has the potential to influence their judgment, they often do not correct sufficiently…

Caruso, Burns and Converse, Slow Motion Increases Perceived Intent, PNAS Vol. 113, No. 33, (last visited January 8, 2024).

Additional research supporting this finding, and the reluctance of courts to apply that science, was detailed in an earlier column in this magazine, “Selective Science.”  36 Crim. Just. 65 (Spring, 2021).  But the issue warrants revisiting in light of a recent and thoughtful Opinion of the New Jersey Superior Court Appellate Division.

In State v. Knight, 2023 N.J. Super LEXIS 129 (decided December 21, 2023), jurors watched several surveillance videos, including one that captured the actual robbery.  The video at issue was replayed at full speed and then in slow motion during the prosecution closing argument; and then during deliberations and at the jurors’ request the video was again played repeatedly in slow motion.

What was the concern?

The video appears to show Osbourne, closely followed by a man the State contended was Kyler, who seemed to be holding onto Osbourne by the neck or shoulder. Walking behind them is another man, who the State contended was Fuquan, holding a black and brown object in one hand. The last man walking in the group allegedly is Shaquan, who does not appear to be holding anything. The robbery apparently occurred off-camera.

Id., *16.  Shaquan Knight’s objection was that although the video caught him doing nothing but walking behind the others, the slow motion distorted judgment and increased the risk of jurors determining intentional involvement.  The defense cited the Caruso study discussed above, which the prosecution at trial labeled “junk science.”

How did the New Jersey Court respond?  It did not deem the study “per se unreliable” but found the circumstances here to be different because these videos “assisted the jurors in resolving critical disputed issues of identification. The video shows the physical appearances of the four men, their sizes, their features, and their clothing. The video also shows where each of three alleged culprits were walking in relation to the victim, and what they individually were doing at that time.”  Id., *26.  As to Shaquan Knight’s argument, the court rejected it because it was phrased as a challenge to assessing his role in the robbery, which was precisely what the jury had to observe and determine.

If the New Jersey outcome paralleled that of other courts that have uncritically approved of slow motion video, why read the Opinion?  Because it acknowledges that caution is warranted and that in some instances the use of slow motion replay may be unfairly prejudicial.  In particular, the New Jersey court acknowledged that in a single perpetrator case, where the issue is intent, “concerns about a slow-motion presentation of the video exaggerating the intentionality of the single actor are likely to be greater.”  Id. 28   The court also suggested guidance for future cases:

  • In exercising their discretion in admitting into evidence or allowing the replay of surveillance video recordings, trial courts should consider, among other things, (a) whether the video has a soundtrack that contains recorded statements of the filmed persons; (b) whether the video is difficult to discern when played only at normal speed; (c) whether the video can assist in resolving disputed issues of identification; (d) whether the video bears upon disputed issues of intentionality; (e) whether the video contains content that is particularly disturbing or inflammatory to watch repeatedly in slow motion.

The court went on to

recommend to the Model Criminal Jury Charge Committee that it consider creating a model charge that specifically addresses situations in which, as here, a jury requests the replaying of surveillance video evidence, and to caution jurors to afford such evidence only appropriate and not undue weight in comparison with the other evidence at trial. Such a model charge might also usefully draw to the jurors’ attention the possibility that viewing such video evidence in slow motion might subconsciously increase their perceptions of an actor’s intentionality

Id., *34-35.


In essence, New Jersey suggests going ‘a little slower’ when deciding whether and how much to permit the use of slow motion replay of crime scene videos.  That bit of caution should be seized upon as video evidence plays a greater and greater role in adjudicating what people thought and meant.