Oakland Police Chief Anne Kirkpatrick visited the young victim and his family at Children's Hospital Oakland and spoke to reporters immediately after.
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"This young man is critically injured and he is one tough guy," she said.
The teenager was hit while riding his bike a week ago near the Fruitvale BART Station. He was trapped underneath and dragged for several blocks.
The driver and a passenger left the scene, but police have tracked down one person of interest.
"We do indeed have a person of interest in custody. We know there is one other person out there and we're going to plead with you - turn yourself in. Call us or come down, because it's just a matter of time," she told us.
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Kirkpatrick says her investigators are zeroing in on the other person of interest, but she won't identify either subject or even tell us their gender.
"I'm still distraught, I'm still messed up about it," says Charles Green, who owns the auto repair shop whose surveillance camera caught the aftermath of the incident and pictures of the victim's injuries. He was pleased to learn about the arrest.
"That's a beautiful thing you know, and I always say, if you hit someone as soon as you leave all bets are off," he says.
Over the weekend the young man was transferred from Highland Hospital to Children's Hospital Oakland. He's reported to be in critical condition in the intensive care unit.