Chicago police officer charged with murder for 2014 shooting of black teen This undated photo shows Laquan McDonald and a Chicago Police car. McDonald was shot and killed by Officer Jason Van Dyke on Oct. 20, 2014. (Fox 32 Chicago) (AP) A white Chicago police officer was charged Tuesday with murder in the 2014 fatal shooting of a black teenager, as the city prepares to release a squad-car video of the incident amid concerns that it will spark protests. The state's attorney's office said in a news release that Jason Van Dyke, who shot 17-year-old Laquan McDonald 16 times on Oct. 20, 2014, has been charged with first degree murder. The judge in the case had ruled that the video, described by some as graphic and deeply disturbing, must be made public by Wednesday -- but sources told the New York Times that its release could come as early as Tuesday afternoon. “In accordance with the judge’s ruling, the city will release the video by Nov. 25, which we hope will provide prosecutors time to expeditiously bring their investigation to a conclusion so Chicago can begin to heal,” Chicago Mayor Rahm Emanuel said last week, according to the newspaper. People who have seen the video told The Associated Press that it shows McDonald armed with a small knife and walking away from officers. Van Dyke opens fire from about 15 feet and keeps shooting after the teen falls to the ground. Police say McDonald, who was found with PCP in his system at the time of his death, was behaving erratically and was refusing to listen to police commands to drop the knife, the Chicago Tribune reports. An autopsy says McDonald was shot at least twice in the back. Dan Herbert, a lawyer for Officer Van Dyke, said the 14-year police veteran believed the shooting was justified because he feared for his safety, the New York Times reported. Fox 32 reported that some investigators were brought to the point of tears after seeing the video. Illinois Gov. Bruce Rauner said state police are working with Chicago officials to ensure people remain safe following the release of the video. Rauner said the video is "very troubling" and that he expects public reaction to be "strong." But he said he hopes and believes the response will be "thoughtful and peaceful." He declined to say whether he's deployed additional troopers to Chicago or put the Illinois National Guard on standby. "This officer didn't uphold the law, he took the law into his own hands," Emanuel said, adding that he had not seen the video. "[He] didn't build the trust that we would want to see, and wasn't about providing safety and security, so at every point he violated what we entrusted him.” Ministers, community leaders and others worry the images could lead to the kind of unrest seen in Baltimore and Ferguson, Missouri, after police-involved deaths. Emanuel called together a number of community leaders Monday to appeal for help in keeping the city calm. But some said after the meeting that city officials waited too long to get them involved -- more than a year after McDonald was shot. "You had this tape for a year and you are only talking to us now because you need our help keeping things calm," one of the ministers, Corey Brooks, said after the meeting. A judge last week ordered the Police Department to release the squad car dashcam footage by Wednesday after the city refused to do so for several months, saying the investigations into the shooting weren't complete. The FBI and the Cook County State's Attorney's Office are investigating. Ira Acree, who described the meeting with Emanuel as "very tense, very contentious," said the mayor expressed concerns about the prospect of any demonstrations getting out of control. Another minister who attended, Jedidiah Brown, said emotions were running so high that there would be no stopping major protests once the video is released. Earlier Monday, Emanuel's office characterized the discussion as something "we regularly do on important topics." But Acree and another minister, Marshall Hatch, said it is a rare occurrence. "We have been trying to meet with the mayor since the beginning of the year to talk about community relations and his staff asks for a letter and says, `We'll get back to you,' but they never do," Acree said before going to City Hall for the discussion. Hatch added: "This has the feeling of them scrambling." Acree and Hatch said blacks in the city are upset about the shooting and because city officials and the Police Department refused for several months to release the video until ordered to do so by a judge. They said people also are angry because the officer, though stripped of his police powers, has been assigned to desk duty and not fired. "They had the opportunity to be a good example and a model across the country on how to improve police and community relations and they missed it," Acree said. The Police Department said placing an officer on desk duty after a shooting is standard procedure and that it is prohibited from doing anything more during the investigations. The Chicago police also moved late Monday to discipline a second officer who had shot and killed an unarmed black woman in 2012 in another incident causing tensions between the department and minority communities. Superintendent Garry McCarthy recommended firing Officer Dante Servin for the shooting of 22-year-old Rekia Boyd, saying Servin showed "incredibly poor judgment" even though a jury had acquitted him of involuntary manslaughter and other charges last April. The Associated Press contributed to this report.