by Larry Danaher, Former Police Captain and Commander, Police-Practices and Security Consultant
Video looks objective because it can be replayed. That appearance of certainty is valuable, but it can also cause a reviewer to give the recording more weight than it can support. A file may accurately preserve everything that entered the lens while remaining incomplete about the event around it. Accuracy inside the frame is not the same as completeness outside it.
The central question should therefore be broader than, "What does the video show?" A defensible inquiry asks three questions: What does the recording directly establish? What can it not establish by itself? What other evidence is needed to understand the event fairly? That framework applies to body-worn cameras, dashboard cameras, fixed surveillance systems, cellphone recordings, and edited excerpts.
The camera view is not the human view
A chest-mounted body camera follows the torso, not the eyes. A person may turn the head, use peripheral vision, shift visual attention, or focus on hands while the camera points elsewhere. The National Institute of Justice has noted that a body camera's perspective is not the officer's perspective unless the device is mounted on the head.1 More recent research comparing body-camera footage with officers' eye fixations and head movement confirms meaningful field-of-view differences during a use-of-force scenario.2
The limitation grows during a dynamic encounter. A participant may be moving, listening to radio traffic, issuing commands, watching several people, using cover, and trying to see both hands. Arms, clothing, another person, a vehicle pillar, a door, or a shield can obscure the precise movement later placed in dispute. An act missing from one recording may have occurred beyond that camera's positional or technical reach. Absence from the frame is not automatically proof of absence from the event.
Technical characteristics matter
Lens design, lighting, stabilization, resolution, frame timing, encoding, and compression can affect how movement and distance appear. Wide-angle lenses may make people seem farther away. Motion blur may conceal the direction of a hand. Automatic exposure may preserve one area while losing detail in another. Variable frame timing can complicate attempts to calculate speed or sequence. Lossy compression can remove information even when ordinary playback appears acceptable.
For those reasons, a screen image should not be treated as a ruler, stopwatch, or reconstruction model without a proper technical foundation. The original or most native available file should be preserved along with associated metadata and audio. Working copies, conversions, enhancements, crops, captions, zooms, and speed changes should be documented. The Scientific Working Group on Digital Evidence recommends examining a file's provenance, content, structure, and integrity rather than relying on metadata alone.3 Its current video-analysis guidance also emphasizes hashing original and working files and documenting processing so results can be reproduced and independently evaluated.4
These safeguards do not mean every case requires a laboratory examination. They mean the reviewer should recognize when a seemingly simple playback has become a technical opinion. If authenticity, alteration, timing, measurement, enhancement, or codec behavior is disputed, a qualified digital and multimedia forensic examiner should address that question.
Audio is evidence, not the entire conversation
Microphones have limitations of their own. Wind, clothing, sirens, distance, overlapping voices, radio traffic, and automatic gain controls can distort or suppress sound. A microphone may clearly capture a nearby statement that another participant did not consciously process. It may also miss words heard by someone positioned away from the device.
Reviewers should distinguish among three separate propositions: what the microphone recorded, what a participant was positioned to hear, and what the evidence supports that the participant actually perceived. Those questions are related, but they are not interchangeable.
Replay can change judgment
A reviewer usually sits in safety, knows the outcome, and can pause, enlarge, and repeat the recording. The participant had to decide without knowing what would happen next. Outcome knowledge can quietly become part of the review unless the evaluator returns to the information available at each decision point.
Slow motion and frame-by-frame review are useful for establishing sequence, but they can also alter perception. Research has found that slow-motion replay may increase judgments of intent because the action appears to have taken longer.5 A sound practice is to begin with complete, normal-speed playback with audio. Slower playback and individual frames should then answer defined questions, not replace the real-time pace of the encounter. When slow motion is presented, the normal-speed version should remain available for comparison.
Video can show contact, position, movement, and timing. It cannot independently reveal whether a movement was deliberate, defensive, reflexive, accidental, or part of another action. Intent must be inferred from the total evidence, including statements, timing, positioning, prior information, physical evidence, witness accounts, and reasonable alternative explanations.
One event, several partial views
Multiple recordings may appear to conflict even when each accurately preserved its own limited perspective. One camera may show a hand. Another may show distance. A third may capture words the others missed. The responsible approach is to synchronize the sources and reconstruct the event, not select the angle that best supports a preferred conclusion.
Synchronization also requires care. Device clocks may be inaccurate, recordings may begin at different moments, and exported files may not preserve the same timing information. Dispatch records, emergency calls, radio traffic, access-control records, photographs, and witness accounts can help establish common reference points. Any estimated alignment should be identified as an estimate rather than presented as exact.
Short excerpts create another risk. A clip may accurately display the selected seconds while omitting the conduct that explains why the participants moved, spoke, or reacted as they did. Cropping can remove a person or object at the edge of the frame. Captions can convert an uncertain sound into a suggested statement. Zooming can direct attention toward one detail and away from the larger scene. Enhancement may improve visibility, but it can also introduce processing choices that must be explained. A reviewer should compare every excerpt or demonstrative version with the complete source recording and clearly label any crop, caption, zoom, speed change, stabilization, or enhancement.
A defensible review sequence
When video may influence a consequential decision, the following sequence creates a more reliable and explainable review:
- Preserve the original or most native available files, associated metadata, audio tracks, proprietary players, and every available camera angle.
- Record the source of each file and maintain an evidence trail; create verified working copies before processing.
- Watch the complete event at normal speed with sound before stopping, zooming, enhancing, or using slow motion.
- Build a synchronized timeline using dispatch information, emergency calls, radio traffic, reports, photographs, physical evidence, and witness statements.
- Identify mounting position, field of view, obstructions, lighting, resolution, frame timing, compression, and audio limitations that may affect interpretation.
- Separate direct observations from inferences. State what the recording establishes, what it does not resolve, and which conclusions depend on other evidence.
- Identify relevant activity outside the frame and the information reasonably available to each participant at each decision point.
- Use enhanced, slowed, or frame-by-frame review only for defined questions; document the process and compare the result with the original normal-speed presentation.
The proper role of video evidence
Video evidence should neither be minimized nor treated as infallible. It may expose misconduct, corroborate a participant, disprove a statement, clarify timing, identify a person, or establish physical movement. Its value comes from using it accurately and explaining its limits.
The most defensible conclusion is built from the totality of the evidence. A camera can be an important witness, but it is a witness with a fixed location, limited senses, no knowledge of context, and no ability to explain what occurred beyond its frame. The governing principle is simple: a camera records what entered the lens. It does not record everything that entered the event.
About the author
Larry Danaher is a police-practices and security consultant, instructor, and expert witness. He served with the Lafayette Police Department, holding the ranks of Sergeant, Lieutenant, and Captain, with police command and SWAT command responsibilities. His experience includes patrol, investigations, critical incidents, training, supervision, and policy development, followed by corporate and global security, executive protection, and school security work. He has taught law-enforcement professionals nationwide in use of force, defensive tactics, officer survival, and leadership, and provides expert analysis and testimony in federal and state police-practices and use-of-force matters for both plaintiff and defense counsel.
References
1. Coppola, M. "Future of Body-Worn Cameras for Law Enforcement." National Institute of Justice, TechBeat, Fall 2013, NCJ 243898. https://nij.ojp.gov/library/publications/future-body-worn-cameras-law-enforcement
2. Murray, N. P., Lewinski, W., Allen, C., Heidner, G. S., Albin, M. W., and Horn, R. "The Eyes Have It! Functional Field of View Differences Between Visual Search Behavior and Body-Worn Camera During a Use-of-Force Response in Active-Duty Police Officers." Police Practice and Research, 2024. https://doi.org/10.1080/15614263.2024.2328664
3. Scientific Working Group on Digital Evidence. Best Practices for Digital Video Authentication, 23-V-001-1.2, March 7, 2024. https://www.swgde.org/23-v-001/
4. Scientific Working Group on Digital Evidence. Best Practices for Digital Forensic Video Analysis, 18-V-001-2.0, December 10, 2025. https://www.swgde.org/documents/published-complete-listing/18-v-001-2-0/
5. Caruso, E. M., Burns, Z. C., and Converse, B. A. "Slow Motion Increases Perceived Intent." Proceedings of the National Academy of Sciences 113, no. 33 (2016): 9250-9255. https://doi.org/10.1073/pnas.1603865113