Now, police are investigating if that gunshot came from a fellow officer's gun in friendly fire.
Eyewitness News has learned the incident was captured on police body camera video, with the suspect apparently yelling "shoot me" as he came toward officers with a 14-inch knife.
Authorities say the man was shot when he refused to put the weapon down, even after they hit him with a Taser, which was ineffective.
A series of shots were fired apparently at close range, with one of those shots hitting the officer in an area that was not covered with his body armor.
"I'm shaken," neighbor Virginia Sturge said. "I still can't believe this."
It happened shortly before 10 p.m. Sunday on Bridge Court in Fort Wadsworth.
Sturge said she walked out of her home to find a chaotic scene, with police involved in a confrontation with her landlord's husband after a report of disorderly conduct.
"Then, I heard bang, bang, bang, and I saw the cop outside calling for backup," she said. "So I had to go back inside the house."
"You can see the male attempting to get past who we believe is his wife and coming at the officers," said NYPD Chief of Detectives Dermot Shea. "You hear multiple times, 'shoot me, shoot me, shoot me', and the ensuing shots, we have up to 10 to 12 shots at this time, preliminary, with multiple striking the victim causing his demise."
Police say that the suspect was drunk and emotionally disturbed. They are still investigating if the suspect had a gun, but so far, no firearm has been recovered.
The officer remains hospitalized in serious but stable condition. Mayor Bill de Blasio visited him at Staten Island University Hospital Monday.
The officer, whose name has not been released, will remain in the hospital overnight. He has been a member of the NYPD just under three years.
Police say these types of situations are among the most dangerous.
"There are two calls that come over the radio that really, it makes police officers think about the job they are about to go to," Police Commissioner James O'Neill said.
"One of them is jobs involving emotionally disturbed persons, and the other is domestic violence calls."
Authorities say this was both. Police have yet to release the body camera video, and the man's identity has not yet been released.
Neighbors said they were in shock.
"It's a little outrageous," area resident Jason Lau said. "I've been living in this little town for 15 years now, and it's the first time I'm hearing about something like this. It's kind of crazy."
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