“I was robbed of watching her grow up, by a man that everyone was supposed to be able to trust to do just one simple task – deliver a Christmas present and leave.”Athena disappeared from the driveway of her home in Wise County, Texas, on November 30.Authorities believe she was killed within an hour of her alleged kidnapping, but her cause of death is still under investigation, Akin said Friday.Warrant: Driver was afraid Athena would get him in troubleHorner told investigators he had accidentally hit Athena as he was backing up his delivery truck and although she was not seriously injured, he panicked and put her in the van before allegedly killing her, according to two arrest warrants obtained by CNN affiliate KTVT.According to the warrants, one issued for each charge, Horner told authorities that he strangled the child because “she was going to tell her father about being hit by the Fed Ex truck.”Horner was tracked down by his employer, a subcontractor of FedEx, after authorities learned Athena went missing around the time a FedEx delivery was made to the home, according to the warrants.“I have felt your prayers, I have read your messages and your letters and I see your pink everywhere.”CNN’s Dave Alsup, Rebekah Riess, Monique Smith and Amanda Jackson contributed to this report."