"[3] He wrote books such as The High Priests of War, in which he criticized the neoconservatives in the Bush administration, and Final Judgment, where he claimed that Israel's Mossad, the CIA and organized crime was responsible for the assassination of U.S. President John F. Kennedy.
He had been criticized by many organizations, including the Anti-Defamation League, the Simon Wiesenthal Center, and the Middle East Media Research Institute, which have described Piper as a promoter of antisemitic conspiracy theories and Holocaust denial.
Regular guests have included Mark Glenn, former candidate for Texas state legislature Barbara Samuelson, and Christopher Bollyn (who occasionally filled in for Piper).
Piper defended alternative medicine, animal rights, and the past activities of Liberty Lobby and Willis Carto.
[7] Piper claimed the assassination "was a joint enterprise conducted on the highest levels of the CIA, in collaboration with organized crime — and most specifically, with direct and profound involvement by the Israeli intelligence service, the Mossad.
The deputy coroner's report stated that the cause of death was a "probable Myocardial Infarction, Ischemic Cardiomyopathy and Coronary Artery Disease", and listed diabetes as another significant condition.