Son of census worker angry case has not been ruled a homicide

It's been almost a month since the body of Bill Sparkman, a U.S. census worker was found dead in the Daniel Boone National Forest.
He was hanging from a tree with the word "fed" scrawled across his chest.
Understandably, his 20-year-old son believes his father was murdered.
He says he can't think of a reason anyone would want to hurt his father but he believes the evidence clearly points to murder.
Josh Sparkman is a soft spoken young man, dealing with the hard reality of losing his only parent.
"He taught me everything I know really. I wouldn't be who I am if it wasn't for him,” said Sparkman.
The death of Bill Sparkman appears to have been a savage attack .
It made national news when the U.S. census worker and substitute teacher was found dead in the Daniel Boone National Forest.
“I couldn't believe it had happened.  I couldn't believe that anyone would hurt my father especially in such a brutal manner,” Josh Sparkman said.
Investigators say he had a rope around his neck and the word 'fed' scrawled across his chest despite being bound and gagged, authorities have not yet said they believe he was murdered.
“You can't do it. How do you accidentally end up that way? You don't so I don’t see how they haven't straight ruled it a homicide,” said Sparkman.
While he struggles to keep up with the details of a headline grabbing case and finding little time to grieve privately, he remembers a father who adopted him at the age of two, volunteered at his school, enrolled him in Boy Scouts and turned him into a math whiz.
“From a young age he was always teaching me more advanced math.  How does he know this? He's three grades ahead,” said Sparkman.
His father's life taken and his now on hold.
Josh Sparkman has inherited a home, a sense of responsibility.
“I want to see justice,” he said, “I would hate to have my dad's case end up as a cold case and never find out exactly what happened or who did this.”
Josh Sparkman says he hopes the census bureau will come up with ways to make the job safer.
He also says he thinks it’s possible his father was targeted for his work with the government.