On November 24, 2015, police release video that captured the shooting of Laquan McDonald in Chicago, Illinois, almost 13 months after the incident took place. There has been a public outcry regarding not only the death of McDonald, but also the videos themselves.
The following blog post clarifies why there could be an absence of audio during the multiple videos released by the city of Chicago from the Laquan McDonald shooting.
Dash Camera Surveillance Systems Record Video and Audio
Video surveillance systems, or closed circuit video recording systems, keep a pre-determined area under security. Not all video surveillance systems record audio. Video surveillance systems in many department stores do not record audio, while those in gas stations, convenience stores and banks often do. Police car dash cam surveillance systems record both audio and video for further officer protection and to deter profiling.
Video Surveillance Systems include Audio Recording
The question remains, why do the videos released by Chicago authorities of the Laquan McDonald shooting lack audio? What are the sounds heard on the video recordings that sound like sirens or whining?
If you watched the videos released thus far, you hear electronic noise. The digital video recorder in the squad car recorded audio, though no audio signal was being sent to the recorder. Was this a technical glitch or did the officers not activate their body microphones? Perhaps they were all muted? Was there a problem downloading the digital recordings from each police car? Who maintains chain of custody logs for handling this evidence?
In an interview for the Associated Press, our lead digital media forensic expert, Ed Primeau, comments on the lack of audio from multiple police cars being a red flag. Additioanlly, fellow forensic expert Gregg Stuchman comments in a second interview for the Associated Press, “It’s plausible for a single squad car to have a glitch preventing sound recording.” Then how could multiple cars not have recorded audio? “I’ve never heard of it before,” Stutchman said. “It raises a red flag. The more likely explanation is that audio was intentionally switched off.”
The Need for a Forensic Investigation
Furthermore, a forensic investigation performed by a neutral, independent forensic expert can determine the reason for the absence of police dialogue and radio communication in the Laquan McDonald shooting. Primeau Foresnics has examined thousands of police dash cam systems. Some include audio, others do not. There are three methods of activating dash cam video and audio.
- The officer activates the recording manually.
- The squad car reaches a certain, predetermined speed for recording to begin.
- The video records when the squad car flashers activate.
Either way, officers have the ability to mute or deactivate their body microphone transmitter. However, the car microphone almost always remains on.
YouTube Fake Squad Car Video
The Associated Press asked Primeau Forensics to examine a YouTube video of the Laquan McDonald shooting that has audio. After careful forensic examination, Ed Primeau concluded beyond a reasonable degree of scientific certainty that the audio track on the video lacks authenticity. Careful analysis of the audio spectrum contained on the video indicates many signs of post event alterations.
Most importantly, we hope this blog post about dash cam video and audio surveillance recordings clears up any misconception about the absence of audio on the Chicago Police dash camera videos.