The shooting happened at the 128th Street Gourmet Deli between Park and Lexington Avenues on 128th Street around 4:00 p.m. on Friday.
Hours later, police were still painstakingly searching for evidence.
Another clue was found in the ice and snow that might lead to the shooter.
The victim of that gunfire, described by police as a 17-year-old boy, was brought out on a stretcher by EMT's and put into an ambulance.
Investigators say he was shot in the thigh and suffered a graze wound to the neck.
They are said to be non-life threatening injuries.
A man named Dee says he is a friend of the store owner and spoke to him not long after the shooting.
"All he knows is somebody shot through the store. I guess they're kids, maybe gangbangers shooting each other. One of the bullets just went into the store through the glass," Dee said.
A large hole could be seen in the front window of the deli where a bullet pierced the glass.
Across the street from the deli, other officers had discovered several shell casings and covered them with plastic cups.
While police have not revealed a motive or whether the teenager was the intended target of the shooting, they say they are looking for four or five young men who are said to have fled the scene.