Focusing for the first time on why attorney general Robert F. Kennedy wasn’t killed in 1963 instead of on why President John F. Kennedy was, Mark Shaw offers a stunning and provocative assassination theory that leads directly to the family patriarch, Joseph P. Kennedy. Mining fresh information and more than forty new interviews, Shaw weaves a spellbinding narrative involving Mafia don Carlos Marcello; Jack Ruby (Lee Harvey Oswald’s killer); Ruby’s attorney, Melvin Belli; and, ultimately, the Kennedy brothers and their father. Shaw addresses these tantalizing questions: Why, shortly after his brother’s death, did a grief-stricken RFK tell a colleague, “I thought they would get one of us . . . I thought it would be me”? Why was Belli, an attorney with almost no defense experience (but proven ties to the Mafia), chosen as Jack Ruby’s attorney? How does Belli’s Mafia connection call into question his legal strategy, which ultimately led to the Ruby’s first-degree murder conviction and death sentence? What was Joseph Kennedy’s relationship to organized crime? And how was his insistence that JFK appoint RFK as attorney general tantamount to signing the president’s death warrant? For fifty years, Shaw maintains, researchers investigating the president’s murder in Dallas have been looking at the wrong motives and actors. The Poison Patriarch offers a shocking reassessment—one that is sure to alter the course of future assassination debates.