The mayor met with Justice League NYC, an organization made of juvenile justice experts, criminal justice advocates, formerly incarcerated people and artists who are calling for change in the criminal justice system.
"The meeting was productive," Justice League NYC wrote on a statement published on their website. "We discussed our demands and pressed (the mayor) on broken windows policing and including community in his new NYPD training program. We look forward to ongoing conversations and a more substantive response from the Mayor and his staff."
Neither Justice League NYC nor the mayor's office returned calls for comment.
Friday's meeting between de Blasio and the protesters come just a few hours before dozens of people have planned to rally in front of City Hall to show their support to the NYPD.
Demonstrators who have been protesting police brutality in recent weeks are expected to come to counter the pro-police demonstration.
Justice League NYC members have organized some of the protests that followed the decision by a grand jury not to indict the police officer who put Garner in a chokehold, killing him.
The group's next protest, Silent March for Justice, is scheduled for this Sunday and will take place in Harlem, according to the group's Facebook page.
Justice League NYC had been calling for a meeting with the mayor since Dec. 8, according to a statement on its website.
The group recently created an online petition in which it listed 10 demands following the grand jury decision on Officer Daniel Pantaleo.
The demands include the immediate firing of Pantaleo and the other officers involved in the incident, the appointment of a special prosecutor to investigate and prosecute criminal cases involving the use of force by police officers and the end to NYPD's "Broken Windows" program, which emphasizes low-level crimes, the statement read.
But the city's Patrolmen's Benevolent Association did not approve of the meeting.
"Mayor de Blasio should not meet with the Justice League NYC until they publicly denounce the individuals who assaulted police officers or who have attempted to incite violence during these protests," PBA President Patrick Lynch wrote in a statement, referring to recent incidents during which protesters assaulted police officers.
The most recent attacks happened during the Millions March NYC demonstration on Dec. 13 when protesters punched two NYPD lieutenants, breaking the nose of one of them and leaving them both with bruises and cuts, according to police, who are still looking for several suspects in this case.
A week earlier, on Dec. 4, a protester was arrested after sucker-punching three police officers during a protest against police brutality.
A spokesman for Justice League NYC told the New York Times his group condemned these attacks.