Neighbors said a dispute between two people escalated into gunfire.
Police said two women in their 20's were arguing. One of the women went to a car. A man in the car then got out and started shooting. The boy, 10, was hit by one of the bullets in the neck.
Investigators have arrested a suspect identified as 29-year-old Lawrence Cook.
City spokeswoman Esmeralda Diaz Cameron says Mayor Cory Booker visited with the boy's family Monday.
The boy was taken to University Hospital. Officials said he was listed in critical condition, but he was expected to survive.
