A FedEx driver panicked after striking a 7-year-old girl in Texas with his work van and threw her in the truck, where he killed her, authorities said.But he killed her after he "panicked" and because "she was going to tell her father about being hit by the FedEx truck the Defendant was operating," the affidavit said.Multiple media outlets reported Thursday Athena's mother, Maitlyn Gandy, saying Horner was delivering Athena's Christmas present, "You Can Be Anything" Barbie dolls, shortly before she was killed.Investigators also learned the FedEx truck was equipped with cameras that captured one-minute clips, the affidavit said.An employee with the FBI, the affidavit said, analyzed video evidence and "found the driver had taken a young girl who was visibly similar to Athena in his van."