Eighteen-year-old Jose Rodriguez of North Plainfield also faces weapons charges stemming from Thursday afternoon's shooting.
He was arrested early Saturday at a Piscataway home. His bail had not been set as of Saturday afternoon.
Authorities say the wounded boy, Jasir Gibson, was not targeted in the shooting and was hit by a stray bullet as he walked with his mother.
He remains hospitalized in critical but stable condition.
A motive for the shooting remains under investigation.
"I took him out for candy, and they started shooting, shooting," said Shante Ford, Jasir's mother.
"She was walking up that way from where the school was and the guy was walking on the street and he just pulled out the gun and started shooting. They said at least seven or 10 went off. I heard nothing," the victim's cousin said.
The shooting happened at South Second Street and Plainfield Avenue. The gunman was said to be aiming at other young males. Ford ran to a nearby gas station cradling her injured child.
Someone there put them both in a car and raced to the hospital. The mayor was not far behind to also be by Jasir's side.
"He kept trying to talk and was saying his throat was hurting him, and everyone in the emergency room was trying to console him," said Plainfield Mayor Sharon Robinson-Briggs.
"This is a tragedy of epic proportions," said Martin Hellwig, Plainfield Police Director.
Plainfield has taken major steps to reduce gun violence. With an innocent child fighting for his life, parents speak out to the culprits of crime.
"Angry, hurt, mad, kids can't even come outside and play," the victim's cousin said.
"Guys out here on the street, just cut it out, for real, because we all have kids," a parent said.
How much peace now has been stolen from this family.
"How are you holding up?" Eyewitness News asked.
"Not good, they shot my baby," Ford said.
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