My deepest sympathy goes out to his family.
For those who don t know who William Cooper was, or have not read much of his writings, I'll offer some of my personal impressions.
1) He will definitely be labeled in the Conspiracy Theory, Lunatic Fringe, Tin-Foil Hat club.
2) With that out of the way, if one attempts to rigorously decipher his in-depth and amazingly consistant themes in conspiracy theories, written from essentially a Judeo-Christian cultural point of view, one is left to ponder how many of his accepted premises are either true, partially true, metaphor for ulterior operations, or perhaps largly true and incredible with a few distracting misinformation tidbits thrown in by others or circumstance to cast a fog of information warfare.
3) His Conspiracy Theories, regardless of truth, obviously touched upon areas of intense Spiritual Warfare. Either he was right on accurate, hence pointing the finger at Satanic occultic conspiracies with incredible consistency, or his theories were false, but so consistent as to tip some occultic plan involving mis/disinformation. E.G. he was close to the target, but it isn't without doubt as to the exact name of the evil object in his theories other than being associated with grand malevolent deception.
4) His infamy or doubt placed on his credibility by those who scoff at possible conspiracy, if anything probably provided additional security for him from ulterior forces.
If anybody is truly threatened surrounding Cooper, it's probably anybody within shouting distance of his papers, files, and personal effects or anybody associated with those surrounding his death. Mainly because the issues he discussed were so incredible that any intel operation would probably devote significant resources to gain absolute control over his possible notes or documentation. Regardless if it was true or false.
5) Isn't it interesting how recent 'terrorists' exhibit demon possessed traits and we are told repeatedly how battle must be waged in underground caverns? in Afghanistan even after numerous fires broke out in US national labs over the past few years. What's interesting is that these little themes are wholly consistent with Coopers musings.