Updated 05/05/16 – 10:46 a.m.

CHICAGO (CBS) — In a surprise reversal Thursday, Cook County State’s Attorney Anita Alvarez asked to recuse herself and her office from the murder case against the Chicago police officer who fatally shot 17-year-old Laquan McDonald in October 2014.

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Alvarez also asked for a special prosecutor in the murder case against Chicago Police Officer Jason Van Dyke. She had previously defended her handling of the McDonald case, and criticized calls for a special prosecutor. She defended the amount of time it took to file charges, saying she was working alongside the FBI and federal prosecutors to thoroughly investigate the shooting and build a “meticulous case” against Van Dyke.

In a statement after Thursday’s hearing in the case, Alvarez said she decided remove herself and her office from the case to avoid any unnecessary delays in the case, and to ensure one specific prosecutor handles the case all the way to trial. Alvarez lost her bid for re-election in the Democratic primary in March. Her eventual successor won’t be elected until November, and won’t be sworn in until December.

“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. Today I believe that I am fulfilling this obligation by requesting that the court turn this case over to a special prosecutor,” she said. “I believe that the results of the recent election and the impending transition of this office make this the best and most responsible decision.”

Cook County Judge Vincent Gaughan said he would not rule on requests for a special prosecutor until June 2.

Two petitions have been filed seeking to replace Alvarez in the case, citing her close ties to the Fraternal Order of Police, the union that represents Chicago police officers. One petition was filed by a group of civil rights attorneys and activists, the other was filed by Rev. Jesse Jackson.

Critics have said Alvarez is beholden to the police union, and has failed to adequately prosecute cases of police misconduct and corruption.

Alvarez stressed she does not believe there is any conflict of interest that would prevent her office from handling the case.

Locke Bowman, one of the attorneys seeking a special prosecutor, said they were surprised and “very gratified” to learn Alvarez is seeking to withdraw from the case.

Defense attorney Dan Herbert said he’s prepared to take the case to trial, no matter who the prosecutors might be.

“While it doesn’t change any of our strategy going forward, it certainly will impact the case in certain regards. We’re going to bring in a new prosecuting crew, who presumably does not have any knowledge about the case, who’s going to have to get up to speed. There’s a lot of documents in this case. There’s a lot of witnesses.”

Meantime, Gaughan announced a special security plan would be in place for future hearings in the case against Van Dyke, after his attorneys asked to have him excused from routine status hearings due to death threats, racial slurs, and harassment as he’s entered and exited the Leighton Criminal Courthouse in the past.

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Van Dyke is free on $1.5 million bail as he awaits trial for first-degree murder in McDonald’s death. He has been suspended without pay.

Gaughan did not provide any details on the security plan, and held off ruling on Van Dyke’s request to be excused from routine status hearings, but thanked Cook County Sheriff Tom Dart for working out extra security measures when Van Dyke will be in court.

The judge said he worked out the security plan with prosecutors, defense attorneys, and the sheriff’s office last week.

“It’s just unconscionable to think that we could compel an individual to appear at a court date without providing for that person’s security,” Gaughan said. “Mob rule will not happen in this courtroom.”

Assistant Cook County State's Attorney Lynn McCarthy looks toward the judge at the Jason Van Dyke hearing on Thursday morning, May 5, 2016 at the Leighton Criminal Court Building in Chicago.

Assistant Cook County State’s Attorney Lynn McCarthy looks toward the judge at the Jason Van Dyke hearing on Thursday morning, May 5, 2016 at the Leighton Criminal Court Building in Chicago. (Nancy Stone/Chicago Tribune/Pool)

Van Dyke is charged with first-degree murder in McDonald’s death, and his attorneys had asked Gaughan to allow the officer to skip status hearings in the case, citing death threats, racial slurs, and large crowds of protesters when he has attended past hearings.

The officer’s attorneys have said Van Dyke’s life has been threatened, his father has been “physically battered,” and a family vehicle has been “smashed” at previous court appearances, and the officer should be excused from attending status hearings in the case to protect his safety.

“There are reasonable grounds to believe that Defendant’s personal safety has been jeopardized by his attendance at previous court appearances and there is reasonable apprehension that the Defendant will continue to encounter the same level of exposure to personal harm in the future,” Van Dyke’s attorneys wrote in their motion seeking to allow Van Dyke to skip some court dates.

Cook County prosecutors opposed Van Dyke’s request to be excused from attending status hearings, noting courthouse protests have died down. They said allowing Van Dyke to miss court when other defendants charged with violent crimes must show up for every hearing would create a “slippery slope,” and create the appearance of special treatment.

Prosecutors have argued Van Dyke has not demonstrated any credible threat to his safety, noting he has not alleged that he has been personally attacked, or that anyone yelling threats has been armed.

“While verbal threats and taunts may create an uncomfortable passage to and from the courthouse, mere words do not jeopardize defendant’s personal safety, and therefore do not necessitate defendant’s absence from court appearances,” prosecutors wrote.

Herbert said Cook County prosecutors first suggested possible protection by Cook County Sheriff’s deputies in their opposition to Van Dyke’s request to be excused from attending status hearings, which typically deal with routine procedural matters.

For most of his court appearances, Van Dyke has needed to run a gantlet of angry protesters when he has appeared at the Leighton Criminal Courthouse. However, at his two most recent court appearances, no protesters showed up as Van Dye attended court.

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The release of police dashcam video showing Van Dyke shooting 17-year-old Laquan McDonald 16 times in October 2014 prompted a series of angry protests across the city, and led to a U.S. Justice Department investigation of the Chicago Police Department’s policies and practices regarding the use of force.