Flanked by police reform advocates and relatives of unarmed New Yorkers who died at the hands of officers, Gov. Andrew Cuomo signed a long-awaited executive order Wednesday that gives the state attorney general’s office authority to investigate cases in which an officer kills an unarmed civilian.

Under this administrative move, Attorney General Eric Schneiderman will independently oversee such cases statewide for a year. Cuomo called the order a “major step forward” and emphasized that he hopes independent investigations would restore the eroded public trust in the criminal justice system.

Police reform groups, including the Justice Committee, lauded relatives for leading the push for a special prosecutor.

“Their tireless advocacy has led this movement in New York to this point,” the group said in a statement. “Their leadership and commitment is an inspiration to us all and what is sorely needed in our state and in this country. This is an important step in the right direction to ending the systemic conflict of interest that exists for local DAs in cases of police killings of civilians.”“A criminal justice system doesn’t work without trust,” said Cuomo. “We have seen it all across the country, where there is a lack of trust in the law enforcement system. We will be the first state in the country to acknowledge the problem and say we’re going to create an independent prosecutor who does not have that kind of connection with the organized police departments.”

Calls for a special prosecutor surged after the death of Eric Garner, an unarmed Staten Island man who was placed in chokehold by an NYPD officer in July 2014. Even though a cellphone video showed Garner being placed in the chokehold, which Police Commissioner William Bratton said is prohibited under NYPD policy, and the city’s medical examiner declaring Garner’s death a homicide, a grand jury declined to indict the officer.

Garner’s death had triggered nationwide anti police brutality protests and calls to reform the state’s criminal justice system. Police reform advocates, including Public Advocate Letitia James, have long argued that district attorneys are too involved with local police who helped them build cases, which, critics say, creates a conflict of interest and a lack of objectivity in cases involving police killings.

Cuomo had pushed for legislation to create an independent monitor to review cases that involve unarmed people killed by police. The governor, a Democrat, failed to reach an agreement with legislators in the Republican-controlled Senate before the legislative session ended. He had promised relatives of people killed by police that he will sign an executive order if Albany failed to act.

“It’s not for our families; it’s for future families,” said Garner’s mother, Gwen Carr, at a rally outside Cuomo’s office in Manhattan Tuesday afternoon, shortly after he made the announcement. “We don’t ever want to see this happen. What happened to my son, millions of people—we don’t know their names; they’re faceless—we want justice for all.”

Carr was joined by dozens of supporters, civil rights leaders and mothers like her.

Constance Malcolm, mother of 18-year-old Ramarley Graham, who was shot and killed by an NYPD officer in the Bronx in 2012, urged Cuomo to act with urgency.

“This is not for us; this is for all the families that come after us,” said Malcolm. “I want to make sure that he keeps his promise that he made to all these families, because we’ve been through it. We don’t want another family to go through it.”

The mothers and relatives demanded that Cuomo sign the “right order.” They want an independent prosecutor for all cases of civilian killings by police, as Cuomo promised when they met him in April. They pointed to the case of Walter Scott in South Carolina, whose death was captured on cellphone video by a bystander. The video showed a police officer shooting the unarmed man and then planting a Taser on him.

Carr said cases like Scott’s show that sometimes police claims are inaccurate.

Whereas Cuomo’s action is seen as prudent by the relatives of victims and police reform advocates, Patrick Lynch, president of the Patrolmen’s Benevolent Association, the city’s largest police union, called it “unnecessary.”

“Given the many levels of oversight that already exist, both internally in the NYPD and externally in many forms, the appointment of a special prosecutor is unnecessary,” said Lynch in a statement. “The rules of law apply regardless of who is investigating a case, but our concern is that there will be pressure on a special prosecutor to indict an officer for the sake of public perception, and that does not serve the ends of justice.”