Transcript for Manhunt underway after teen shot dead in suspected road rage incident

And a man in the red pickup truck pulled out a gun. And shot her in the head. Killing her eighteen year old Bianca Roberson was on the other end and that they are all her car veered off the southbound lanes of route 100 and crashed. Now there's a manhunt for her killer. And they were jostling for position or whatever and unfortunately this gentleman took it to the degree that is just unconscionable and highway cameras reveals she and this driver of a red pickup truck had some sort of altercation minutes before speeding out of control. This second photo shows the red pick up truck moments after the crash fleeing the scene now on to load teal and a belt to get on pioli pike. The good girl honor roll student. The record to won't. Choking back tears Robbie Roberson says the music is eighteen year old daughter's dad hasn't sunk in I hope it's not beyond cut that's what beyond his grandmother said to herself as she passed the crash site but the intention of meeting up with her at home. Her own grandmother had no idea that the traffic she was sitting and was caused by her granddaughter's death not when there and then when she saw the police she said she had. This crazy feeling police were already at the house to notify beyond the Stanley that she had died on scene she's so young mind what's going through something like that ourself. She ended in pretty scared Iago was heading to Jacksonville university in two weeks for orientation. With the goal of solving cases for the FBI. Authorities that they had this message for her murder or turn yourself in now. Every second you're out there you are only making this worse for yourself. And worse for this young lady spam.

This transcript has been automatically generated and may not be 100% accurate.