Just as the NYPD was releasing final guidelines for its body camera program, top police unions were filing a legal challenge against it. NY1's Courtney Gross filed the following report.

The NYPD is ready to roll out its massive body camera program. But not before some police unions have their say.

"At the moment, I am trying to prevent the city from implementing a policy that has not bargained with the police unions," said Roy Richter of the Captains Endowment Association.

The detectives', lieutenants' and captains' unions are filing legal papers challenging the NYPD's new body camera procedures. The head of the captains' union told us the unions believe the body camera program should be the subject of collective bargaining. 

The program was part of contract negotiations between the city and the Patrolmen's Benevolent Association. The higher-ranking unions are now following their lead, even though it is just officers wearing the cameras. 

"My members will be responsible for the implementation of the body camera program. They are going to be held accountable for its success or its failure," Richter said.

The move came Friday afternoon, just hours after the NYPD released new guidelines for how officers should operate the cameras. 

The program is slated to start this month in the 34th Precinct in Washington Heights.

The guidelines will require officers to tell the public they are on camera, unless it would impede their safety or an investigation. 

Police officers are required to turn on the cameras for lots of reasons, including arrests and vehicle stops.

By this fall, about 1,200 officers in 20 precincts across the city will have them. 

This follows a pilot body camera program with just 54 officers in 2015. NY1 is suing to get access to the video footage from that program.

Moving forward, while some police unions were looking to potentially block the program, advocates are giving the new guidelines a mixed review. 

"We think the policy could go further. But we think they have done a good job in a lot of respects," said Molly Kovel of the New York Civil Liberties Union. "We are excited to follow along and see how it goes."

The NYPD says it has been working on this policy for about a year. Now, it is time for them to put it into practice.