Video footage shows the officer allegedly responding to a stabbing harlem on 7 July.
In the video, the officer can be heard shouting, “Go get me a bag of potato chips now.”
“Go over there and get me the tapes,” he then ordered an onlooker.
The officer then laid the victim on the ground with the help of others and used bags and tape to stop the bleeding.
WARNING: Graphic Body Cam Video Footage
An ambulance arrived quickly and took the victim to the hospital.
Chief Rodney Harrison tweeted, “This is just one example of the heroic work your NYPD officers do every day.”
Police arrested Eric Rodriguez, 38, and charged him with attempted murder, assault and criminal possession of a weapon, police said.
Rodriguez and the victim, who had not been identified by police, were involved in an altercation when the violence unfolded.
A note on the video tweeted by NYPD Commissioner Dermot Shea read, “According to the attending physician at Harlem Hospital, the officer’s actions saved the victim’s life.”