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Researchers: Allow officers to watch BWC footage after writing an initial report

A study of Dutch police officers found that the officers who were able to watch their BWC footage of a training exercise wrote more accurate and complete reports


YouTube/ Maryland OAG Independent Investigations Division

By Annelies Vredeveldt, Ph.D., and Linda Kesteloo, LL.M.

More and more police officers around the world are being outfitted with body-worn cameras (BWC). The footage obtained from police BWCs can be used for various purposes. For example, the footage can help police officers reflect on their own performance, serve as training videos for other officers, or be used to gain investigative leads.

Another potential role for BWC footage is as a direct or indirect contribution to the evidence in criminal cases. BWC footage can contribute to the evidence directly, if the footage itself is submitted to the trier of fact for consideration, or indirectly if the footage informs police officers in the process of writing the police reports that will be submitted into evidence.

Objective Reality Myth

When BWC footage is submitted into the evidence directly, it is important that efforts are made to mitigate potential risks. Specifically, there is a risk that the trier of fact falls prey to the objective reality myth, which is the idea that video footage can reveal some sort of absolute truth about what happened. This idea is mistaken.

There are myriad reasons why the BWC footage may not reflect accurately what actually happened. For one, research shows that the quality of the footage is often lacking, for example, because there is too much movement, or because the lens is dirty, facing in the wrong direction or covered by the officer’s hands or clothes, or because the camera was turned on only after crucial events had already happened.

Furthermore, experiments have revealed that observers’ interpretation of what happened during a filmed event is heavily dependent on the context in which the footage is presented and the background and beliefs of the observer. For example, in one study, university students who watched footage of a police shooting came to very different conclusions about what happened and how justified the officer’s actions were than police recruits who had watched the same footage.

Even if the footage leaves little room for interpretation about certain aspects of the event (for example the suspect clearly puts his hands up), but does not correspond with what is written in the police report (for example, the police officer writes that the suspect did not put his hands up), observers should be aware that such discrepancies can be explained in light of insights from legal psychology.

Scientific research shows that police officers’ perceptions and memories are heavily influenced by stress, expectancy effects, divided attention and social contagion. This could result in a police officer genuinely remembering that the suspect did not cooperate, even if the footage shows that they did. Thus, if there is a discrepancy between a police report and BWC footage, the trier of fact should not automatically assume that the police officer is lying.

Review of BWC Footage by Police Officers

BWC footage can also contribute to the evidence indirectly if police officers review the footage before writing their police report or before giving testimony in court. A potential benefit of reviewing BWC footage is helping police officers refresh their memory and correct memory errors.

At the same time, however, a review of BWC footage has the potential to impair memory for aspects of the event that are not shown, due to a cognitive process called retrieval-induced forgetting. For example, if a police officer sees only one of the two get-away cars on the footage, this may lead the officer to provide a detailed description of that car in the police report, but completely forget to mention the other car (which the officer probably would have done if the officer had simply started reporting based on their own memory).

Reviewing BWC footage can also result in confusion about the source of specific memories. Police officers can become convinced that they observed a certain detail during the event, whereas they actually only saw it later in the footage. In addition to these memory processes, the existence and review of BWC footage can lead to intentional restriction of information, such as making the description less detailed to reduce the risk that the officer will be ‘caught’ making a mistake. Or intentional misrepresentations of the event, such as downplaying potentially illegitimate use of force because it was not captured on camera.

BWC research

To examine more concretely how the review of BWC footage affects police reports, we conducted a field experiment with approximately 100 Dutch police officers. They participated in a training exercise in pairs, involving the arrest of a somewhat aggressive suspect. Shortly afterward, each police officer wrote a police report about the arrest, either before or after watching the BWC footage of the event.

In our research, police officers who wrote their reports before watching the footage were allowed to revise their reports after watching the BWC footage. We found that reports that had been revised after watching the footage were significantly more accurate and complete than the original reports. We concluded that the review of BWC footage can have added value for the truth-finding process in criminal cases, as long as police officers write down their own memories before watching the footage and are transparent about any changes they make after watching the footage.

Based on our findings, we recommend that police departments allow police officers to watch BWC footage, but only if they have written down their memories in an initial report first. That way, officers can use the footage to expand and correct their memories in the final police report. It is crucial that police officers keep a copy of their initial report and indicate in the final report where they have made changes based on what information, such as the precise timestamp of the footage where it shows that things went a little differently from what they remembered.


BWC footage can have evidentiary value. Nonetheless, an apparent discrepancy between BWC footage and a police report does not necessarily mean that the footage should be believed at the expense of the police officer. Our field experiment showed that if police officers use available BWC footage to revise and expand their police report, it can lead to better reports.

Read more: Find more information about the field experiment in our open-access scientific journal article: To watch or not to watch: When reviewing body-worn camera footage improves police reports. Law and Human Behavior, 45(5), 427–439.

About the authors

Dr. Annelies Vredeveldt is an associate professor at the Department of Criminal Law and Criminology at VU Amsterdam. She is co-founder and director of the Amsterdam Laboratory for Legal Psychology (ALLP). Her ERC Starting Grant research team investigates eyewitness testimony in cross-cultural settings. Dr. Vredeveldt regularly appears as an expert witness in criminal cases and serves on advisory committees of the Netherlands Register of Court Experts and the Dutch National Police. She teaches the Psychology course in the International Law in Society program at the VU and coordinates Project Reasonable Doubt, in which potentially dubious criminal convictions are re-evaluated.

Linda Kesteloo, LL.M., is a lecturer/researcher in criminal (procedural) law at the Department of Criminal Law and Criminology at VU University Amsterdam. In 2013, she was awarded the NWO grant ‘research talent’ for her Ph.D. project. Her research addresses safeguards for witness reliability from a legal perspective. In 2016, she collaborated with Annelies Vredeveldt and Peter van Koppen on a research project about the influence of collaboration between police officers on the content of police reports. She is currently working with Annelies Vredeveldt on the bodycams research project.