Kinsey, a private eye, was involved in an accident. Along with some other people. The person who seemed to have caused it was Caroline who ended up dying.
After the accident Caroline's mom visited Kinsey. Saying that her daughter had been murdered. And that she got into the accident because she had been shot. She then asks Kinsey to look into it and find who killed her daughter.
Kinsey visited the roommate. She asked questions but the roommate wasn't giving direct answers. Kinsey later on found a lead when she found the license plate number of the truck in the accident in a photo that was taken at the scene.
Kinsey went to the roommates family home, only to find the same truck from the accident. And in the truck lays the gun used to kill Caroline.
The killer was coming home and about to turn into the driveway when he saw Kinsey. He took off and Kinsey followed him in a high speed chase through town. Till they crashed and the killer died in the same place where he killed Caroline.
The killer ended up being the person the suspected the most. The guy in the blue pickup truck. He died in the accident which just happened to be the same spot where he killed Caroline.