CNN  — 

Cook County State’s Attorney Anita Alvarez has taken herself and her staff off the murder case against the police officer accused of wrongly killing Chicago teenager Laquan McDonald.

At a hearing Thursday, Alvarez asked Judge Vincent Michael Gaughan to appoint a special prosecutor in the case against Officer Jason Van Dyke.Gaughan said he would announce his decision on June 2.

“My primary goal in bringing a charge of first-degree murder in this case is and always has been about seeking justice for Laquan McDonald,” Alvarez said in a statement. “Today I believe that I am fulfilling this obligation by requesting that the court turn this case over to a special prosecutor.

“While it has not been an easy decision, I believe that it is the right one because it will help to avoid unnecessary legal delays and provide continuity in the handling of this very important and complicated case,” she said.

Alvarez lost the Democratic primary for state’s attorney in March so she would likely not be in office throughout the high-profile case. She had faced heavy criticism over her handling of the case.

Civil rights leaders who had called for a special prosecutor applauded Alvarez’s move.

“We were quite frankly surprised and also very gratified to learn this morning that Anita Alvarez is seeking to recuse herself from the prosecution of Jason Van Dyke,” said one of the attorneys, Locke Bowman.

“We agree with the sentiments expressed in State Attorney Alvarez’s brief filing, that the interests of justice and fairness for this community require this step on her part.”

Van Dyke has pleaded not guilty to six counts of first-degree murder in the 2014 death of McDonald, 17, whose videotaped shooting provoked anger nationwide.

Dashcam video of the shooting, which a judge ordered released in November over the city’s objections, contradicted nearly everything police said happened the night of October 20, 2014.

It showed McDonald veering away from police as he held a knife, not lunging toward officers as police had said.

Van Dyke jumped out of his vehicle and pulled his gun, firing at McDonald six seconds after arriving on the scene. The two never faced each other in the encounter. Van Dyke continued to fire, unloading every round from his 9-mm Smith & Wesson handgun in 15 seconds.

The video appears to show McDonald’s body getting hit by bullets even after he was on the ground. The video released to the public has no audio.

All 16 rounds struck McDonald.

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The release of the video after a 13-month legal battle prompted protesters to take to the streets in Chicago, chanting “16 shots and a cover-up.”

A mayoral task force set up after the shooting said police “have no regard for the sanctity of life when it comes to people of color” and have alienated blacks and Hispanics with the use of force and a longstanding code of silence.

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Van Dyke, who has been suspended without pay, is free on bond.

He is the first Chicago officer charged with first-degree murder since 1980.

CNN’s Wayne Drash, Rosa Flores and Bill Kirkos contributed to this report.