Dash cam video of the Laquan McDonald shooting was released by the Chicago police department. Although most dash camera video recordings include an audio track, this dash cam video did not include audio. In a heightened state of concern, concerned citizens believed that the audio portion of the video recording was intentionally deleted or altered.? Did the equipment malfunction or is there another reason why the audio portion of this incident was not recorded? In the meantime, a video of the same incident, allegedly with audio, was posted on YouTube. Concerned citizens believed that this video was genuine and included the missing audio. Primeau Forensics was asked to investigate the YouTube video and offer an opinion as to the authenticity of this second version of the dash cam video that included audio.
During our investigation of the YouTube video titled ?Is this the audio? Chicago Police dashcam video of Laquan McDonald shooting?,?we?discovered several anomalies and inconsistencies that scientifically revealed the second YouTube video is a fake. Using Time Domain Analysis, Frequency Domain Analysis, and Critical Listening Skills we have outlined these anomalies and inconsistencies below.
Frequency Analysis:
In the image above, the Spectrogram reading shows the cutoff frequency of the gunshots well above the cutoff frequency of the noise floor (background noise, radio chatter & siren). A display of the difference in frequency content between the gunshots and background noise is displayed in the image below. The gunshots are represented by the red vertical sections.
The cutoff frequency of the audio content from the YouTube video titled ?Is this the audio? Chicago Police dashcam video of Laquan McDonald shooting? is around 16 kHz. This is displayed in the image below:
Based on my experience, audio recorded evidence produced from law enforcement vehicles contain a cutoff frequency of 4 kHz. I have examined the frequency analysis of the audio recorded in the original video ( the video with no audio- lack of radio communication & officer dialogue). The cutoff frequency analysis of the original audio portion of the video recording is 4 kHz and displayed below:
Based on my forensic testing and analysis, I can confidently say that the audio portion of this second YouTube video has been manufactured and added to the video after the original video was created. Why would anybody add audio to a video recording? In an attempt to deceive and make the video more powerful with a fake audio track. The video recording with the fake audio deceives the viewer. Although it appears to be real, it is indeed fake.
- The original video released by Chicago Police contains recorded audio content of cross-talk, and alternator or engine noise (see above image). The noises that are audible within the original video recording are low in amplitude but can be heard with a significant increase in volume. Because this digital recorder in the police car recorded an audio track, it is my opinion that the digital video recorder was functional and had the ability to record sound. Because of the lack of officer dialogue and radio chatter, we believe the lack of these sounds was due to the following reasons:
- The on-person lavalier microphones within the vehicle were muted
- The on-person lavalier microphones within the vehicle were disconnected
- The on-person lavalier microphones within the vehicle were deactivated
- The gunshots, and radio chatter heard throughout the YouTube video titled ?Is this the audio? Chicago Police dashcam video of Laquan McDonald shooting? are duplicated, equalized and are not genuine or authentic. Previously in this blog I discussed the inconsistency between the cutoff frequency of the gunshots and cutoff frequency of the background noise within the audio content. In addition, the audible fingerprint of the gunshots within the Spectrogram has a distinct shape, size, and intensity that are consistent with duplication or repetition. The frequency decay of the gunshot, timbre or sound of the gunshot, as well as duration of the sound are almost identical. The gunshots are displayed in the image below:
The radio chatter sample at timecode 0:04.387 (MM:SS:MS) is an exact duplicate of the radio chatter sample 0:03.000 (MM:SS:MS). The conversation being spoken is identical. The difference between the two is that the duplicate has been processed using equalization to deceive the listener into believing it is additional radio conversation.
This video claiming to have genuine audio is indeed a fake. The Laquan McDonald Police Video With Audio is Fake.
