Jasper Killed Dr. Cortes
Warning This Section Does Contain Spoilers
There is a body in the woods that looks distinctly feminine from the buttocks and size of feet and hands. Because Sylvia met a female Dr. Cortes when she came to the gates of the facility in episode four and the Sheriff mention a male Dr. Cortes in episode four and then a female Dr. Cortes in episode five, it is a good possibility that the body in the woods is Dr. Cortes. Jasper is most likely posing as Dr. Cortes and has been for a while, since episode two when the Sheriff first made his appearance to the facility. This would also explain why the "female doctor" is living in the patient dorms next to the urinals.
There has been some thoughts that the body in the woods is the landscaper because the grounds are unkept, but if Dr. Cortes is no longer alive, there is no one around in charge to force the landscaper to do his duties and he is just getting lax in his duties.