NEW YORK (CBSNewYork) – The rookie NYPD officer who shot and killed Akai Gurley in a Brooklyn public housing development was indicted Tuesday.

As CBS2’s Weijia Jiang reported, sources told CBS2 a grand jury indicted NYPD Officer Peter Liang. Specific charges will not be revealed until the indictment is unsealed, and Liang is arraigned, on Wednesday, CBS2’s Dick Brennan reported.

READ MORE: Storm Watch: Officials Hoping To Avoid Repeat Of Ida With Preparations For Nor'easter

The Brooklyn District Attorney’s office would not confirm Liang’s indictment late Tuesday, but was set to hold a news conference on Wednesday afternoon.

The indictment will give the jury the opportunity to decide whether there was criminal negligence or recklessness involved, and whether a crime was committed, 1010 WINS’ Sonia Rincon reported.

As WCBS 880’s Alex Silverman reported, multiple reports say the top charge against Liang is second-degree manslaughter, which carries up to 15 years in prison.

“The arraignment of Police Officer Peter Liang, tomorrow is the first step in getting justice for the reckless shooting and wrongful death of Akai Gurley,” family attorney Scott Rynecki said in a statement.

Kimberly Ballinger, Gurley’s domestic partner and mother of his son, will also address the media following Liang’s arraignment, Rynecki’s statment said.

In praising the grand jury’s decision in the Gurley case, Rynecki referenced the grand juries that declined to indict the officer involved in the deaths of Michael Brown and Eric Garner late last year.

“We’re very pleased. I know that the public at large has lot of faith in the justice system given what happened in Ferguson and in Staten Island. However, when Ms. Ballinger and I met with the Brooklyn District Attorney’s office, we came out of that meeting with full faith and confidence,” he said.

NYPD Commissioner Bill Bratton said Officer Peter Liang and his partner were going into a stairwell from the eighth floor of the Pink Houses public housing complex in East New York on Nov. 20 of last year, while Gurley, 28, and his girlfriend were going down the stairs from the seventh floor.

Police sources told CBS2 that Liang was trying to open a door while holding a gun, and the gun went off accidentally, hitting Gurley in the torso.

Gurley was taken to Brookdale University Hospital and Medical Center, where he was pronounced dead.

Sources said it was “pitch black” in the public housing corridor because the lights were broken. Police classified the incident as an “accidental discharge,” and the reason he had his gun drawn remained unknown Tuesday.

Gurley’s death was classified as a homicide by the New York City Medical Examiner’s office shortly after the incident, but cautioned that the ruling “does not imply any statement about intent or culpability.”

But Gurley’s family has always maintained the incident amounted to murder.

READ MORE: NYPD: Man Shot Inside Union Square Subway Station

“He hasn’t done anything wrong,” Gurley’s mother, Sylvia Palmer, said tearfully following the incident. “He is a good man – good. He loved his family; his baby girl.”

Liang was placed on modified duty following the incident. Sources said a grand jury started hearing the case against him this past Wednesday.

Liang was expected to turn himself in on Wednesday.

The Rev. Al Sharpton’s National Action Network released a statement Tuesday afternoon saying it was pleased by the announcement of Liang’s indictment and “pleased that the process will now allow for a fair and impartial hearing.”

“Unlike the case in Staten Island, this case shows the difference in a prosecutor who will respect the grand jury’s role to decide probable cause, rather than attempt to influence it. We will monitor this to make sure there is a fair process,” Kirsten John Foy said, Northeast Regional Director for NAN.

Patrick Lynch, president of the Patrolmen’s Benevolent Association, said in a statement: “This officer deserves the same due process afforded to anyone involved in the accidental death of another. The fact (that) he was assigned to patrol one most dangerous housing projects in New York City must be considered among the circumstances of this tragic accident.”

“This officer deserves the same due process afforded to anyone involved in the accidental death of another. The fact the he was assigned to patrol one most dangerous housing projects in New York City must be considered among the circumstances of this tragic accident.”

Mayor Bill de Blasio also released a statement late Tuesday afternoon.

“It has been reported that a Brooklyn grand jury has acted in this case. No matter the specific charges, this case is an unspeakable tragedy for the Gurley family. We urge everyone to respect the judicial process as it unfolds,” the mayor said in the statement.

Brooklyn Borough President Eric Adams said he hoped the indictment would help reconcile the public’s relationship with the criminal justice system.

“An indictment in this case allows the judicial process to move forward, a process that should be fair and transparent. An indictment helps to restore public confidence in our legal system, a confidence that was thoroughly shaken following the outcome of the Eric Garner case in Staten Island,” Adams said in the statement. “It is my continued hope that the death of Akai Gurley will give life to much-needed reforms that will make the community and law enforcement alike safer.”

Gurley’s family announced plans in January to sue the City of New York for $50 million, claiming the officer acted recklessly.

Following Gurley’s death, the New York City Council Committee On Public Housing held a hearing to investigate the relationship between lighting and safety.

MORE NEWS: Exclusive: CBS2 Cameras On Hand At Unannounced Security Screenings At Troubled New York City High Schools

The Housing Authority acknowledged that when Gurley was killed, the stairwell had a fluorescent light that had failed due to a ballast problem, leaving only the ends of the bulbs dimly glowing, WCBS 880’s Rich Lamb reported.