Footage from inside the shop, published by the New York Post, shows the moment the child’s mother, as she’s about to pick up the infant, notices the injuries.
The mother then becomes hysterical, and starts jumping up and down with her hands clasped behind her head.
Emergency services were called at 13:21 local time (17:21 GMT).
The child was taken to nearby Woodhull Hospital where she was pronounced dead. Police reported no one else killed or injured in the incident.
“As a mother, I cannot imagine the pain that this family is feeling or the grief that they now carry with them,” Tisch said. “It is unspeakable.”
Footage seen by police showed the suspects crashing into a car shortly after fleeing the scene.
Both suspects were thrown from the moped – but the rear passenger landed so hard he lost “both of his shoes”, Tisch said.
An ambulance was called for the injured man who was brought to Brooklyn Hospital, where he was then taken into police custody.
Investigators said they believe he fits the description of the shooter, based on the clothing he was wearing and his appearance, but he was taken into custody as part of an unrelated investigation.
No one has been charged in the shooting.