Police on Saturday were looking for a gunman responsible for killing two teens and wounded a third person in Pomona.
The incident began before 1:19 a.m. when police received numerous calls of shots heard in the 300 block of Orchid Lane.
The victims were identified as 13-year-old Justin Hansen and 17-year-old Andy Chavez, police said.
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A memorial continued to grow Saturday evening for the slain boys whose friends said were "always together" and not in a gang.
A friend of Chavez told NBC4 that a third teen was walking with the pair when the attack happened, but escaped unharmed. He suspects the shooting was gang-related, though he does not believe the victims knew their attackers.
"A couple guys asked them where they are from. They're like we don't bang. They told him to pick up your shirt. When he picked up his shirt, they shot at him for no reason," said the boy, who requested anonymity.
Officers found the older victim dead at the scene. The 13-year-old was found in a nearby alley. He was taken to a hospital where he died. A third person -- the driver of a black car upon which the shooter opened fire -- was wounded and taken by helicopter to a hospital where he was listed in critical condition.
Police had not determined a motive by late Saturday.
Chavez's friend, Stephanie Valdez, said she can't help but blame herself for the teen's death.
"'Cause I didn't pick him up," she said. "I didn't have my car, so I had no choice."
Valdez provided a photo of the boys, pictured at right.
A witness, who did not want to be identified due to safety concerns, said she saw two men open fire on a black car. The man driver tried to get away, but slammed into the side of an apartment unit and then hit a parked blue car. She said the shooters fled and she called 911.
Another witness said she was asleep with her granddaughter when the black car blowed into her front room. No one in the apartment was hurt, she said.
Anyone with any information is urged to call the Pomona Police Department Homicide Detectives at 909-620-2095.