HARLEM, Manhattan (PIX11) — A 36-year-old man was fatally shot in the head inside a smoke shop in Manhattan Sunday night, police said.

The gunman opened fire as the victim was leaving the store at 304 Lenox Ave. in Harlem just before 8 p.m., according to the NYPD. The suspect shot the man twice in the head, including once while he was on the ground, police said.

Police are investigating the possibility that the shooting was the result of a drug deal gone wrong, and the gunman and victim knew each other, sources told PIX11 News.

The shooting was captured on surveillance video in the store. The gunman can be seen showing the victim his gun. Words were then exchanged between the two. The victim lit a cigarette and started to walk away. That’s when the gunman shot the man.

The video shows the chaos after the shooting. People in the smoke shop ran out. The gunman walked away but then returned and shot the victim again in the head.

The victim was taken to a hospital and pronounced dead. He was not an employee of the smoke shop, according to police.

The shooter ran from the smoke shop and was last seen heading northbound on Lenox Avenue toward West 126th Street, police said. No arrests have been made.

Submit tips to police by calling Crime Stoppers at 1-800-577-TIPS (8477), visiting crimestoppers.nypdonline.org, downloading the NYPD Crime Stoppers mobile app, or texting 274637 (CRIMES) then entering TIP577. Spanish-speaking callers are asked to dial 1-888-57-PISTA (74782).