Now we're learning more about the 16-year-old victim and the teenager accused of killing her.
According to court records, the shooting may have been gang-related.
Deputies say they're still trying to figure out if both groups were in a rival gang or a party crew.
Grief counselors were brought in to the school the victim attended, Cesar Chavez High.
18-year-old Jason Christopher Lindsey, Jr. didn't have anything to say during his first court appearance. Prosecutors asked a judge to set his bond at $1 million.
"Pulled up next to this car stopped.. he obtained or had the gun.. pointed it out the window.. shot a number a times at one of the passengers in the car," said the prosecutor.
Niani Allen died after being shot in the head. Her friends drove her to a nearby Walmart store to try and get help.
"She always had a smile on her face and she would come up to me and give me a hug and stuff and we would just talk," said Richard Jones, a friend of the victim.
"She was a pretty cool female. She just got caught up in the wrong stuff and the wrong time," said Deboy Simmons, another friend.
Just after the shooting, Lindsey was arrested at his mother's apartment in Phoenix.
Deputies say they're still trying to figure out why Lindsey shot at the car Allen and her three friends were riding in. Investigators believe Allen and her friends got into an argument with Lindsey at a girl's basketball game at Sierra Linda High School on Friday. The violence happened minutes after both groups left the game.
"They need to stop. It's pointless. It's not going to get you anywhere but in a jail cell or in a grave," said Jones.
For now, Lindsey is being held on $1 million bond. He's facing a murder charge and three assault charges for the other passengers in the car he allegedly shot at.