I had read about this happening, and it is a shame. Apparently, he was another investigative reporter who "crossed the line" like Michael Hastings did, and had been being threatened for several years. After his last book, he pretty much backed out of the spotlight, and even stated that he was going to stop reporting the controversial issues, hoping the attacks would then stop.
One can only assume that they must have been still threatening him with harm to his family, or some other serious things, to drive this man to kill himself.
Another patriot pushed over the edge, but from what I read, they believe that he did in fact take his own life and was not "suicided" like most of the others we have lost recently.