Chicago police must release a dashcam video that shows the October 2014 fatal shooting of a black teenager by a white officer, a judge has ruled.

The city already has paid a $5 million settlement to the family of Laquan McDonald, 17, who was shot 16 times. A federal investigation of the shooting is ongoing.

But the Chicago Tribune reports the video allegedly shows the officer firing several shots into McDonald as he lay on the ground.

Cook County Judge Franklin Valderrama says the police department must make the video public by Nov. 25. The city has no plans to appeal the ruling, the Chicago Sun-Times reports. The judge also denied the city's request for an immediate stay of the ruling.

"Police officers are entrusted to uphold the law, and to provide safety to our residents," Mayor Rahm Emanuel said in a statement, according to NBC News. "In this case unfortunately, it appears an officer violated that trust at every level."

Emanuel had said as recently as last week that it would be inappropriate to release the video during an ongoing investigation, the Tribune reports.

The officer involved in the shooting, Jason Van Dyke, is on paid desk duty during the investigation. His lawyer, Daniel Herbert, tells the Tribune that the video shows only one perspective and is not "clear-cut."

"The video is graphic, disturbing and difficult to watch, as any video of a man being shot to death would be," Herbert tells the Tribune. "It's impossible from viewing the video to determine exactly what my client was experiencing at the time in which he fired the shots. ... It's not showing from his eyes, which is an important distinction."

Chicago Police spokesman Anthony Guglielmi tells the Sun-Times the police department is preparing for a possible violent response from protesters when the video is released. Mike Robbins, the lawyer for McDonald's family, and the teen's mother, Tina Hunter, also are concerned about reaction to the video, NBC News reports.

According to NBC News, a lawyer for the family says the video shows the teen was holding a small knife. The Tribune adds that McDonald was acting erratically and refusing police commands to drop the knife as he walked along a city street. The Sun-Times reports that at one point McDonald punctured the tire of a squad car with the knife and also struck its windshield.

The teen was walking away from officers when one suddenly opens fire and continues to shoot while McDonald lays prone on the ground, reports say.

An autopsy showed that McDonald had PCP in his system.

Robbins says the McDonald's mother has not seen the video.

"We've talked to her at length about this," Robbins tells the Tribune. "What mother would want to see the execution of her son over and over again on the nightly news or on YouTube? She is in therapy, she is in counseling and does not want to see it."

But Robbins tells the Sun-Times that it's important the public "be told the truth."

"The fact that there was a narrative put out there by the Chicago police, by the union initially, that a police officer had to shoot [McDonald] in self-defense, that he was approaching a police officer and lunged at a police officer with a knife, is not true," Robbins said. "He was shot while he was walking away."