An Atlantic City teen already held on a gun charge was ordered detained Friday in a shooting that wounded a man and woman in December.
He shot nine times into the passenger side of the parked vehicle, striking each of the victims including one in the head, according to the complaint.
"The victims had nowhere to go because they were constrained as essentially sitting ducks in the vehicle," the judge said in rendering her decision.
There has been no information released on the alleged co-conspirators.
Cooper is connected with a gang, according to court filings referenced at the hearing.
"It shows motive and it shows dangerousness of the defendant and it shows he's part of a network that does have resources and the ability to flee," Assistant Prosecutor Chris D'Esposito told the judge, although he did not mention the gang by name or detail the motive in the shooting.
He already was being detained on the gun and drug charges when he had his detention hearing in the shooting.
The discussion of his cases included clarification that ballistics showed the gun he was arrested with was not the one used in the shooting.
"It shows that in a six-day span he was able to acquire two separate firearms ... and that he didn't have any hesitation to use one," D'Esposito told the judge.
But defense attorney Yvonne Maher argued that shows there is no physical evidence tying Cooper to the shooting.
Maher also said she has no evidence of witness identification of her client, who was linked to the crime by surveillance video that she has not seen.
Cooper has no other adult charges, but had only turned 18 about two months before the alleged crimes.
As a result, Judge Dorothy Garrabrant noted that it was appropriate to look at his juvenile criminal history, which is fairly extensive.
His adjudications as a minor include burglary, receiving stolen property, attempted burglary, conspiracy to commit theft, conspiracy to commit burglary, prohibited weapons and devices, unlawful possession of a handgun, aggravated assault, simple assault and a probation violation, the judge said.
"Defendant's juvenile sanctions did nothing to rehabilitate him," she said, adding that it instead shows an "extreme escalation of defendant's violent criminal conduct."
Cooper remains in the Atlantic County Justice Facility on both cases.