After Chicago police last week released video footage of Laquan McDonald's shooting more than a year after the incident took place on Oct. 20, 2014, protesters are demanding to know what happened to the audio that should have been included in the videos recorded by police cruisers at the scene.

Although public outrage over the police shooting and handling of 17-year-old McDonald has led Chicago Mayor Rahm Emanuel to fire Chicago Police Superintendent Garry McCarthy, protesters are still demanding answers to important questions surrounding this case.

In the dash-cam video, the African-American teen is seen walking in the middle of a two-way street, when multiple police cars drive toward him. Then, just six seconds after arriving on the scene, Officer Jason Van Dyke jumps out of his vehicle and opens fire on McDonald, who was armed with a knife and had PCP in his system, according to a criminal complaint filed in Cook County Circuit Court.

"Questions my 8th grdrs had today re #LaquanMcDonald's murder: How could 5 different police cars have broken audio on their cameras?" tweeted @GregoryMichie on Monday.

According to Ed Primeau, a Michigan-based audio and video forensics expert, sound is a criticial component in understanding why the officer and suspect acted the way they did, reports The Associated Press.

Without hearing the corresponding audio, it's difficult to determine when the shooting started and stopped; if there was a pause in between the shots; and what was said before, during, and after the shooting.

Police spokesman Anthony Guglielmi initially suggested that the absence of audio was most likely a technological glitch.

"As with any technology, at times software issues or operator error may keep the cameras from operating as they normally should," he wrote in an email.

However, Primeau said it is unlikely that all of the police vehicles at the scence did not have working audio.

"It's a red flag," he said. "I see it all the time -- not just by police, but by people trying to cover things up."

In addition, a district manager for a Burger King near the shooting scene named Jay Darshane told reporters that several police officers entered his restaurant to then delete surveillance video of the shooting recorded by the restaurant's cameras.