i am so sorry for what happened. if you live where there is a large animal control presence, maybe something can be done. if you live in small town texas, maybe not so.
spent a lot of time helping out in shelters, rescues, transport of non-human animals. this is not unusual as awful as that is to hear. it's hard to understand why the police,animal control did not tell you not to have any of your animals outside when you weren't home after you complained. worse things have happened to dogs/cats in situations like this.
you may have no option other than move. please do not leave animals unattended outside. you remember michael vick? vick and his pals used to drive around suburbs, find unattended dogs, take them, and throw them to his fighting pit bulls to kill.
we live in terrible times. i know you and your family loved your little dog very much and that the dog knew it. many dogs never know love or kindness. we hope for the best for your family.