Over a dozen investigators cordoned off a two block crime scene from East 119th Street to 121st Street.
Video appears to show the moments before the shooting, as a man in a blue hoodie can be seen through the doors of a local supermarket, knife in hand.
It all started around 1:15 a.m. when the 53-year-old man got into an argument with someone before having to be physically removed. Police say the man was harassing the workers there and was kicked out by staff.
"Following the dispute, the male suddenly became irate and disorderly and had to be physically removed from the store by multiple employees," NYPD Inspector Andrew Natiw said at a press conference.
Police say the man returned with a 13-inch kitchen knife just before 1:40 a.m.
About three workers at City Fresh Market took photos and video of the man as he waved the knife around.
He was "banging on the window with the knife," prompting store employees to lock the door and call police.
Police say that when their officers arrived, attempts were made to try to get the man to drop the knife, but he advanced at them.
That's when officers took aim, striking the man in the stomach once.
"The officers gave multiple verbal commands to drop the knife and attempted to create physical distance between himself and the subject," Natiw said.
The man was taken to Harlem Hospital, where he is in critical but stable condition.
The knife was recovered at the scene.
No police officers at the scene were injured during the incident but those involved were taken to the hospital to be evaluated.
Police later identified the suspect as 53-year-old Carlos Santiago.
When asked whether the man is an emotionally disturbed person, police could not comment, but say he had five prior arrests prior to Monday's shooting.
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