Child killer Tanner Horner sang the holiday song "Jingle Bell Rock" as he was brutally murdering little Athena Strand in the back of his FedEx truck in late 2022, Texas jurors learned late Thursday, April 16, while continuing to hear evidence as they determine what punishment the 35-year-old delivery driver deserves: death or life in prison. Horner pleaded guilty to capital murder and aggravated kidnapping on April 7, just as his criminal trial was set to start.