They say the driver shot into the car just ahead, with Christian in the backseat.
A bullet hit the Chasco middle school 8th-grader in the head, and he died Saturday.
Investigators say they don’t know yet what led to the violence.
But they also released a sketch of what the shooter may look like.
Christian’s mother says she doesn’t know what happened either.
“But somebody does. Somewhere. And they just need to, not only for me, but for his memory give him justice. Somebody knows something.”
Tanya says Christian was looking ahead to high school and picking electives.
He loved music and his friends.
“I find myself for instance walking past his bedroom, and I always look in in the morning before school, and he wasn’t there. It’s just like he’s at a sleepover or something. It hasn’t hit me yet,” she said.
Crime stoppers of Tampa Bay is offering a reward of up to $3,000 for information leading to an arrest.