The case tested the liberal mayor's relationships with both civil rights activists, who have long complained that the city's black and Latino residents are harassed by police, and the rank-and-file police officers who work for him, some of whom say they have been made scapegoats by his office.
The city's police commissioner terminated Officer Daniel Pantaleo following the recommendation of a police department disciplinary trial.
De Blasio said Monday he hopes Commissioner James O'Neill's decision to fire Officer Daniel Pantaleo "brings some small measure of closure" to the family of Eric Garner.
Eric Garner died after being placed in a chokehold by Pantaleo during an arrest.
The incident sparked "Black Lives Matter" protests calling for police to be held accountable for the deaths of unarmed African-Americans in custody or facing arrest. Quickly, Garner, who weighed about 400 pounds (180 kilograms), appeared distressed gasping, "I can't breathe", at least 11 times before he fell unconscious.
"That could possibly be me".
"You can appeal all you want, I'm still out here, I'm out here for the long run. and you cannot scare me away", Garner's mother, Gwen Carr shot back. However, she added that it should have done five years ago.
Mr Garner's daughter, Emerald Snipes Garner, thanked Mr O'Neill "for doing the right thing".
He spoke at length in unusually emotional remarks, saying he had empathy for Pantaleo, who had been following orders from his supervisors to crack down on loose cigarette sales, and that he expected police officers would question his decision.
JAMES O'NEILL: Every member of law enforcement in this country that works and keeps this country safe and this city safe looked at that and said, that could possibly be me.
Mayor Bill de Blasio said that this decision was fair and evenhanded and justice has been served. In 2015, New York City paid a $5.9 million settlement to Garner's family to avoid a civil lawsuit.
'The preponderance of the credible evidence established that Respondent's use of a prohibited chokehold was reckless and constituted a gross deviation from the standard of conduct established for a New York Police officer'.
"There are absolutely no victors here today", said O'Neill, calling it a hard decision that he made "unaffected by public opinions" in the widely debated case.
O'Neill noted that the NYPD ranks would be unhappy with the decision and Pantaleo's treatment, and took time to praise Pantaleo as "a hardworking police officer with a family, a man who took this job to do good, to make a difference in his home community [who] has now lost his chosen career". He called Garner's death an "irreversible tragedy" that "must have a outcome".