Gov. Andrew Cuomo has signed an executive order that appoints Attorney General Eric Schneiderman as the special prosecutor to investigate cases where a police officer kills an unarmed civilian, or when there is a question if a civilian is armed and dangerous.

New York is the first state to appoint a special prosecutor to investigate police-involved shootings. Calls for independent reviews started last year after Eric Garner was killed in Staten Island, and Michael Brown was killed in Ferguson. Grand juries in both cities declines to indict the police officers who killed the unarmed men.  

Speaking at John Jay College on Wednesday, Cuomo said the past year has shown the "crisis of trust" between the minority community and criminal justice system.

"Our goal is to reverse the energy ... and start to build trust again," Cuomo said. 

"Equal justice under the law is not just a slogan engraved on our courthouses, it's the essence of what the United States is about," Schneiderman said. 

Mothers of men and women who have been killed by police officers attended the signing.

"We chose not to lay down and give up, we had to stand up and fight," said Constance Malcolm, whose son, Ramarley Graham, was unarmed and killed by an NYPD officer in the Bronx in 2012. "We're in a boat no one wants to be in, and i can say right now, it's crowded."

Malcolm, along with Eric Garner's mother, Gwen Carr, and other surviving family members rallied outside of Cuomo's Midtown office on Tuesday, calling for him to keep to the stipulations he made in closed-door meetings with them earlier this year. 

Pat Lynch, president of the city's largest police union, said on Tuesday that the special prosecutor is "unnecessary."

"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," Lynch said in a statement.