If the person did indeed die of homicidal violence, like a gunshot or shotgun blast to the chest, that would be an "open" invitation to every vulture, crow, mouse, rat, opossum, raccoon, coyote, blowfly, etc in the neighborhood. And the area has a river running through it, which increases the amount of wildlife.

Also, it's a relatively moist area, which seems to contribute to decomposition, as opposed to the mummified remains found under dry conditions.

Sue