The family of Delrawn Small says they plan to file a $25 million wrongful death lawsuit against the city.
Officials say Small was shot and killed by off-duty police officer Wayne Isaacs after a road rage incident the morning of July 4.
It happened near Atlantic Avenue and Bradford Street in East New York.
Initial reports claimed Small punched Isaacs several times before he was shot, but surveillance video shows Isaacs fire his gun as soon as Small reaches his window.
Police say Small was unarmed at the time.
His widow, Wenona Small, says she wants to prevent an incident like this from happening again.
"No one should have to go through what I'm going through, his children, his family. I want justice for my husband," Wenona Small said. "We want justice so this doesn't happen to anybody else's family."
"This was an unjustified killing, a man walking towards a car and, a second later, shot in the head," said Sanford Rubenstein, Wenona Small's attorney.
Isaacs has been placed on modified duty.
State Attorney General Eric Schneiderman has been appointed special prosecutor to investigate Small's death.