Why kill him?Doubt it personally.
People do kill themselves under high pressure, this type of conscientious white male at higher rates than others .
Work all your life to get into high back room positions only to find that you have to throw it all away in the public spotlight....He knew that those hearings and his evidence meant the end of his career......plus poor health and old age.
To me it was always a very plausible suicide.
The dirt was already out there in the public domain. He had nothing left on anyone. "The government made me skew the document?" We already knew that.