A California district attorney is urging the gunman involved in the road-rage killing of a six-year-old boy to turn themselves in immediately, ahead of the expected burial Saturday. 

Orange County District Attorney Todd Spitzer sent a message Friday to the killer of Aiden Leos, who was shot May 21 while riding in a car with his mother on State Route 55.

"Look, you are wanted for very serious crimes. You killed a little six-year-old boy. For God's sakes, turn yourself in," Spitzer told "America Reports." "Do you understand the devastation you have caused? You know, you need to stand up and be accountable for the crime."

REWARD IN SUSPECTED ROAD RAGE SHOOTING OF CALIFORNIA 6-YEAR-OLD UP TO $450,000

The reward for information that helps lead to an arrest in the Leos shooting has climbed to $500,000. Government officials and community members have pooled together half a million dollars in the hopes of finding the driver suspected of shooting the boy.

Investigators are searching for a white 2018 or 2019 Volkswagen Golf SportWagen with a sunroof.

The community paid tribute to Leos by decorating Yorba Linda Boulevard with turquoise ribbons, which was his favorite color. 

"You know, his parents should be talking about how he's doing in school, not having to bury their child tomorrow afternoon," Spitzer told co-host Sandra Smith. 

Joanna Cloonan, the boy’s mother, said she was cut off by a couple in what appeared to be a white Volkswagen. She said a bullet went through the trunk of the car moments later and struck the boy. 

"She watched her son die in her arms. I mean, it's every parent's worst nightmare," Spitzer said. 

CALIFORNIA DA URGES GUNMAN IN ROAD RAGE KILLING OF A 6-YEAR-OLD TO GIVE UP

He continued to express his frustration over the case.

"Don't be on the run anymore. Turn yourself in. This nation is coming to the rescue of this little boy, they want justice in this case," Spitzer said. "I'm pretty sick and tired of the fact that you're expending all these resources and you want to make a little boy be buried tomorrow while you're still on the run. Turn yourself in and at least try to explain why you would kill a little boy in cold blood."

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For any information regarding this case, please contact 800-TELL-CHP. 

Fox News’ Stephen Sorace and Louis Casiano contributed to this report.