Noel Polanco was shot by detective Hassan Hamdy during a traffic stop in Queens back in 2012.
Hamdy fired through the car window because he said he thought Polanco was reaching for something under his seat.
There were no weapons in the vehicle.
A grand jury cleared Hamdy of criminal wrongdoing, but the family settled a wrongful death claim for $2.5 million earlier this week.
Appearing Saturday at the National Action Network, Polanco's mother, Cecilia Reyes, said the detective should not be working in law enforcement.