The families of several police-shooting victims fumed Tuesday that the de Blasio administration is shamelessly kowtowing to ex-tennis star James Blake after his false arrest.

“Black lives matter. Latino lives matter. Non-­celebrity lives matter,” was the angry message of about 15 protesters outside NYPD headquarters in Manhattan.

The group included relatives and supporters of Akai Gurley, a 28-year-old dad shot dead last year by cops while walking in a dark housing-project stairwell in Brooklyn; Anthony Baez, a 29-year-old who was killed by police in 1994 after hitting a police car with a football in The Bronx; and Nicholas Heyward Jr., who was playing with a toy pistol when he was shot by a cop at age 13 in 1994.

“Bratton was police commissioner 21 years ago when my son was murdered, and I used the word murdered because that is what it is when you shoot an innocent human being,” said Nicholas Heyward Sr.

“Was I able to get the opportunity to meet with the mayor at that time, who was Mayor Rudy Giuliani? No, I was not.

“I also made attempts to reach out to this mayor here, de Blasio. Was I able to reach him? No, I was not . . . Why wasn’t I able to get an apology from anyone?”

Mayor Bill de Blasio and NYPD Commissioner Bill Bratton have profusely apologized to Blake after he was body-slammed by a cop who mistook him for a credit-card scammer outside a Manhattan hotel about two weeks ago.

The top city officials even privately huddled with Blake on Monday to discuss what he thought the department could do to curb violent cop behavior.

By doing so, Bratton is selling out the plainclothes cop who took down Blake, Officer James Frascatore, law enforcement sources told The Post.

“In all the years I’ve been on the force, and that’s a very long time, I have never seen anything quite like this,” said one veteran official.

“They just threw this cop under the bus immediately — put all of his information out there and a video of the incident — and all of this without even starting the internal investigation.”

Frascatore was put on desk duty after the Blake incident. He was summoned before the Civilian Complaint Review Board last week, with one source describing the hours-long meeting as highly contentious.

Three detectives who were present during Blake’s arrest were also brought back to the scene last week to re-enact what they were doing at the time, sources said.

In addition, they have been questioned three times by the NYPD’s Internal Affairs Bureau and twice by the CCRB, according to sources.

The CCRB has four videotapes that capture what happened from different angles, sources said.

A de Blasio spokeswoman responded to Tuesday’s rally by saying that Hizzoner has been “focused on moving our city forward by building trust and restoring the bonds between police and the communities they serve.”

The NYPD refused to comment.

Additional reporting by Shawn Cohen and Yoav Gonen