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Laquan McDonald Police Video With Audio is Fake

Friday, December 4th, 2015

On November 24, video of the Laquan McDonald shooting was released by the Chicago police department – video that did not have audio. Subsequently, a video of the same incident, allegedly with audio, was posted on YouTube. I was asked to take a look at the video and offer my professional opinion as to the authenticity of the audio portion.

During my investigation of the YouTube video titled “Is this the audio? Chicago Police dashcam video of Laquan McDonald shooting”, I discovered several anomalies and inconsistencies using Time Domain Analysis, Frequency Domain Analysis, and Critical Listening Skills. I have outlined these anomalies and inconsistencies.

Frequency Analysis:

Frequency_Analysis_Laquan

  • In the image above, the Spectrogram shows the cutoff frequency of the gunshots well above the cutoff frequency of the noise floor, or background noise (radio chatter & siren). A closer look at the difference in frequency content between the gunshots and background noise is displayed in the image below:

Frequency_Analysis_Laquan_2

  • 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:

Frequency_Analysis_Laquan_3

Based on my experience, audio recorded evidence produced from law enforcement vehicles contain a cutoff frequency of 4kHz. I have examined the frequency analysis of the audio recorded in the original video evidence with lack of radio communication & officer dialogue. The cutoff frequency analysis of the original video evidence is displayed below:

Frequency_Analysis_Laquan_4

Based on my testing and analysis, I can confidently say that the audio portion of this video has been manufactured and added to the video. For what purpose? Only the ‘creator’ of the video can answer that.

Frequency_Analysis_Laquan_5

  • The original video released by Chicago Police contains recorded audio content of crosstalk, 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 recorded an audio track, it is my opinion that it was functional and had the ability to record sound. Because of the lack of officer dialogue, radio chatter, we believe the lack of these sounds was due to the following reasons:
  1. The on-person lavalier microphones within the vehicle were muted
  2. The on-person lavalier microphones within the vehicle were disconnected
  3. 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:

Frequency_Analysis_Laquan_6

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 Video Recordings of the Shooting of Laquan McDonald

Thursday, December 3rd, 2015

Laquan McDonaldOn November 24, 2015, police video that captured the shooting of Laquan McDonald in Chicago, Illinois was released to the public, 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 are closed circuit video recording systems that keep a pre-determined area under security by recording video and audio. Surveillance video cameras aid in deterring and documenting crime and other activity.

Some video surveillance systems record audio, others do not. Video surveillance systems in many department stores do not record audio. Video surveillance systems in gas stations, convenience stores and banks often do record audio, as well as video.

Police car dash cam surveillance systems record both audio and video for two reasons:

  1. To protect the police officer
  2. To deter profiling

Video Surveillance Systems like the ones used by the Chicago Police 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 that have been released so far, electronic noise can be heard. This is defined as electronic cross talk. The digital video recorder in the squad car was recording audio, that is why we hear that whining sound. The problem is that no audio signal was being sent to the recorder. Was it a technical glitch or did the officers elect not to activate their body microphones? Perhaps they were all muted? Was there a problem downloading the digital recordings from each police car? Who has the chain of custody logs for the handling of this evidence?

In an interview for the Associated Press, our lead Audio Video Forensic Expert, Ed Primeau, comments on the lack of audio from multiple police cars being a red flag.

In a second interview for the Associated Press, published by ABC News, fellow Audio Video Forensic Expert Gregg Stuchman comments that ‘It’s plausible for a single squad car to have a glitch preventing sound recording.’ 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 reality of this situation is that a full forensic investigation needs to be performed by a neutral, independent Audio Video Forensic Expert in order to determine the reason for the absence of police dialogue and radio communication from the audio portion of the digital video recordings released in the Laquan McDonald shooting.

We have examined thousands of police dash cam systems here at Primeau Forensics. Some include audio, others do not. There are three methods of activating dash cam video and audio.

  1. The officer activates the recording manually
  2. The squad car reaches a certain, predetermined speed for recording to begin
  3. The video is engaged in record when the squad car flashers are activated

One important note; the officers have the ability to mute or not activate their body microphone transmitter should they decide. However, the in 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 of the  video, Ed Primeau concluded beyond a reasonable degree of scientific certainty that the audio track on the video is fake. Careful analysis of the audio spectrum contained on the video indicates many signs of post event alterations.

We hope this blog post about dash cam video and audio surveillance recordings will help clear up any misconception about the absence of audio on the Chicago Police Dash Camera Videos.