Video shows the suspect walk up to a man and open fire.
It happened Sunday morning on Bruckner Boulevard in the Soundview section.
Police say 27-year-old Ezequiel Rivera was shot in the chest.
Rivera was rushed to Jacobi Hospital where he was pronounced dead.
The gunman is seen walking into a Story Avenue building with a blue sweatshirt on and then walking out of the location wearing a white t-shirt.
Anyone with information in regard to this incident is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782).
RELATED: At least 4 killed in shootings over weekend in NYC
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