The body found last week in the Bridger-Teton National Forest was likely an assisted suicide, not a murder, the Teton County Sheriff's Office said Wednesday.
A man running with his dog discovered the body of the 66-year-old man about 50 yards off Mosquito Creek Road on Thursday and officials initially treated the case as a murder.
An autopsy Monday night showed the man had cancer in the upper part of his body. There were indications he had narcotics in his system, but investigators are awaiting the final toxicology report.
A note found on the man's clothing said he believed everything was beyond hope for him, and he wanted to die.
Authorities said although they believe the man did write the note, they don't believe he was capable of carrying out his own death alone. After talking to the man's wife, they said they believe the death was an assisted suicide.
The body was not buried, but dumped in the woods.
The man's head was severed likely due to an animal, the sheriff's office said.
The name of the man and the name of the person believed to have assisted in the suicide are not being released.
The investigation is continuing.