Dagoberto Costanon agreed to let a judge sentence him for murder and two counts of failing to stop and render aid.
Thirteen-year-old Ethan Vasquez was killed in April of 2014.
Highland Park officers chased a stolen minivan into the M Streets neighborhood of Dallas. The police backed off, but the van ended up slamming into the car Ethan and his mother were in.
Costanon and another man jumped out of the van and got away. They were later arrested in Florida.
The second man's attorney claimed he was a passenger in the van and not involved in the murder. He was only charged with a probation violation.
Castanon sat at the defense table in jail stripes as prosecutors laid out their case in during the sentencing hearing on Tuesday afternoon.
Richardson police officer Chad Moore reconstructed the violent accident and an animation played in court showing how the collision happened. Moore said the van ran a stop sign and plowed into the car at a high rate of speed.
The medical examiner testified Vasquez died from multiple blunt force trauma and the impact was so violent the base of his skull completely separated from his spinal cord.
The state brought a number of police officers who testified to Castanon's history of stealing vehicles, running from the police and running stop signs in residential area.
Ethan was a seventh grader in the talented and gifted program at Travis Middle School. He was also the son of a Cedar Hill police sergeant.