Stephen Quick said the letter, which arrived earlier this month in an unmarked envelope, bore the presidential seal and included a message signed by the president.
"I could see that the black ink was bleeding through, and I was like, 'Oh, this is the real deal,'" Quick said.
In the letter, the president wrote, "Melania and I are devastated by the senseless loss of your beloved son, Caleb. We are heartbroken for your entire family."
Quick said he had written to the White House months earlier but did not expect a response. The letter also included a broader message about public safety, stating, "Please know my Administration will never stop fighting to clean up our streets and ensure law and order in our Nation."
Quick described receiving the letter as both surprising and meaningful.
"Getting a response in general was very shocking, but amazing, but also validating. My son mattered, and I feel like these laws don't give any matterness to victims. They sympathize more with criminals than they do with victims," he said.
The letter comes amid ongoing legal proceedings tied to Quick's death. Prosecutors recently attempted to move the case of the accused teen getaway driver to adult court but were unsuccessful under the standards set by California's Proposition 57.
Another key hearing is expected in the coming months for the teen accused of pulling the trigger.
Quick said the president's message has renewed his efforts, along with dozens of other families who have lost children to youth crime, to push for changes to Proposition 57.
"We're going to be protesting big time. We're going to demand change to Prop 57. No more 'we're not going to send killers to criminal courts,'" he said.
Quick said a protest is planned at the state capitol on Aug. 13. Attorneys are also expected to determine shortly afterward whether the fall transfer hearing for the accused gunman will move forward.
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