The cops were responding to 911 calls, reporting a black man in a jacket pointing a "silver firearm" at people, who NYPD Chief of Patrol Terence Monahan says "took a two-handed shooting stance" and pointed at them, according to several US media reports.
Four officers, three in plainclothes and one in uniform, fired 10 rounds among them, striking the man.
The man was rushed to a hospital where the he was pronounced dead.
However, it was then that they discovered the man had not been holding a gun, but a pipe with a knob at the end, the reports said.
Stephon Clark, an American black man who was shot dead last week after two law enforcement officers misunderstood him as an accused of breaking car windows in California, was shot eight times in his back, according to an independent autopsy.