Police announced the arrest of 19-year-old Rasul McNeil-Thomas on Friday evening. McNeil-Thomas was arrested at his Newark home and charged withmurder of Newark Police Officer William Johnson.
He was also been charged with two counts of aggravated assault for shooting two other victims and weapons charges. Bail has been raised to $1,500,000.
There was no immediate word on whether he had retained an attorney.
Police are still searching for the second suspect.
The Thursday night attack killed 45-year-old Officer William Johnson, a 16-year police veteran.
A 21-year-old man was wounded and was in stable condition at University Hospital. A 19-year-old woman who was at the restaurant with her toddler was struck in the shoulder. She was released from the hospital by Friday morning. Her child was not wounded.
Johnson, known in the department as an affable, dedicated officer, worked in the department's video surveillance unit, monitoring police cameras set up around the city, and alerting officers in the streets to any suspicious activities.
"There is still a deep sense of pain for the loss of this officer," Newark Mayor Cory Booker said. "But there is a sense of gratitude, of pride and relief that (investigators) are getting to the closing strides to find who is responsible for these crimes."
Authorities said McNeil-Thomas and the other suspect stole a car at gunpoint and used it in the shooting; the car was recovered nearby soon afterward. They didn't say what tied McNeil-Thomas to the car or whether he had identified the second suspect.
Acting Police Director Samuel DeMaio said video surveillance from inside the fast-food place showed that the shooting happened so quickly, Johnson would not have had time to draw a weapon.
The vehicle from which the shots came sped off immediately, authorities said. DeMaio said there were multiple shots fired; he didn't provide an exact number but said it was fewer than 10.
Details on a possible weapon used were not immediately released.
Johnson was off-duty when he stopped by Texas Fried Chicken and Pizza to order something to eat. Surveillance video showed he was standing at the counter, waiting for his food when the shooting occurred, according to DeMaio.
The bullets came from a vehicle outside the restaurant at about 9:50 p.m.
Police say there were more people in the fast-food place than the three who were shot, and one of them may have been the intended target. They were asking the public's help in tracking down any witnesses who may have been inside the restaurant or in the vicinity.
The slain officer grew up in Newark and continued to live in the city that often ranks as one of the nation's most dangerous places.
He had two daughters and was not married.
He was declared dead just after 3 a.m.
"The tragedy of this senseless killing is compounded by the fact that the victim, Officer Johnson, was a man who devoted his professional life to protecting the City of Newark and its residents from this type of violence," said state Attorney General Paula Dow.
Violent crime has risen in Newark in the last two years, despite gains in 2007 and 2008. There were twice as many murders, 20, in the first three months of this year, compared with last year, according to police department statistics.
The increase has come after much-publicized layoffs that cut nearly 15 percent of the police force at the end of last year. One of the officers who was laid off, 24-year-old Natombe Simmonds, collapsed and died while playing basketball last week, making this a particularly painful time for the department, police officials and the mayor said.
"This is a very sad day for us, our city is deeply, deeply wounded. We are in agony," Booker said, adding they wouldn't stop until they found whoever killed Johnson. "We are determined. We are steadfast. We will find (these) individuals."