As Chicago prepared to make public a video from the fatal shooting of a black 17-year-old by a white Chicago police officer, a state prosecutor charged the officer with first-degree murder on Tuesday, reports the New York Times.

The charges against the officer come more than a year after the shooting, but only days after a judge ordered Chicago officials to release the video from the shooting, captured by a dashboard camera in a police car. The judge had ruled that the video, described by some who have seen it as graphic and deeply disturbing, must be released by Wednesday.

Anita Alvarez, the Cook County state's attorney, said in a statement that the officer had turned himself in to the authorities and was scheduled to appear at a bond hearing later on Tuesday.

Dan Herbert, a lawyer for the officer, said the 14-year police veteran believed the shooting was justified because he feared for his safety.

At one point, Laquan McDonald, whose autopsy showed the presence of the drug PCP in his system, pounded on the windshield of the squad car and punctured its front tire with the knife, city officials say.

A lawyer for Mr. McDonald's family says the video shows Mr. McDonald, who the authorities say had a knife, moving away from Mr. Van Dyke. In April, the city agreed to pay $5 million to the family even before a suit had formally been filed in the case.

"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," Mr. Emanuel said last week. On Monday, he met privately with community leaders and pastors, and some who attended said he had called for calm.