Authorities say 43-year-old Purcell Gowie was shot and killed on East 116th Street on Wednesday night.
Officials say he walked into a dispute between three or four men before he was shot in the chest.
He is believed to be an innocent bystander.
Gowie helped the poor and homeless at a nonprofit located just blocks away from the scene of the shooting.
The suspect police are looking for is described as a male with a thin build, approximately 18 to 25 years old, and was last seen wearing a black jacket, jeans and black and white sneakers.
So far no arrests have been made.
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