No doctor but for the unfortunate poor lad the slicing looks sharp and surgical, they appear random at first glance but are not. I'm going with victim of a killer or medical experimenting after death. No blood apparent so he was staged for the photo and took a beating to the head possible C.O.D.
I agree with you, and I think he's been decapitated -- his head looks like it's just propped up on his shoulders.
Maybe the decapitation was his cod.