I have found deer like that near my place too. Not as many in 1 place though. We came upon 4 one year that seemed to have died next to each other. Asked the neighbors if they were dumping, I let them know I was just curious and it was no big deal, no one knew anything about it. Most definetly one was poached in you case. I assumed mine just went there to die, for whatever reason, natural causes or bad shots. It was very near a pond and they will go to water when death is around the corner. Was it near water?