Activists affiliated with the Black Lives Matter movement disrupted Mayor Bill de Blasio’s remarks at a pre-K event Thursday, demanding NYPD changes and asking why the cop who fatally shot an unarmed Bronx man in 2012 is still on the job.

The demonstrators hoisted signs as de Blasio stood at a lectern. They questioned why the officer, Richard Haste, hasn’t been fired four years after shooting Ramarley Graham, 18, inside the Bronx apartment of the victim’s family.

“I have a 5-year-old brother, and he asked me if black lives matter to you. Do they?” one of the protesters asked the mayor, as his bodyguards approached to kick the demonstrators out.

“Yes, they do,” said the mayor, who won the mayoralty on a platform that included making the NYPD fairer to minorities.

Two of the protesters later identified themselves as high school janitor Jennifer Escobar, 26, of Corona, Queens, and construction worker Sam Hartley, 29, of Bedford-Stuyvesant, Brooklyn.

Graham was shot to death on Feb. 2, 2012. The NYPD said the cop mistook a gesture by the teen as a reach for a weapon. A state grand jury had initially indicted Haste but the case was dismissed because of a prosecutorial error.

In March, the U.S. attorney for the Southern District of New York, Preet Bharara, announced there was insufficient evidence to charge Haste with a federal crime, spurring an angry response from Graham’s family and activists.

De Blasio has refused to meet with Graham’s mother, Constance Malcolm. At the Thursday event, protesters wanted the mayor to explain his reasons.

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“Why are you afraid to look her in the eye?” one protester asked the mayor.

“Again, we’re addressing the issue,” de Blasio said. “There is a process. Right now, we’re here to talk about pre-K.”

De Blasio told the protesters he won’t meet with Malcolm because Haste is in the process of being disciplined. The demonstrators said de Blasio met with tennis star James Blake last year after a cop was caught on video tackling him in a case of mistaken identity.

During his mayoral campaign de Blasio promised to “bring police and community together,” by reining in the police practice of stopping and frisking mostly black and Latino young men who had not committed a crime.

The addition of a court-appointed monitor has led to reductions in the NYPD practice but de Blasio has continued to tangle with activists who say he’s not doing enough to change the NYPD.