Hw did confusing evidence and weaknesses in a government investigation lead to an avalanche of conspiracy theories? The proliferation of conspiracy theories across social media today may seem like a hazard of the digital age, but it has ties to a home movie taken by a Dallas businessman more than 50 years ago. Abraham Zapruder was among the thousands of people who turned out in Dallas on November 22, 1963, to catch a glimpse of President John F. Kennedy. Zapruder aimed his 8mm Bell & Howell home movie camera at the president’s motorcade as it rolled by, and by chance captured the assassination on film. Because the film appeared to show that Kennedy was shot in the front of the head, the film stirred controversy. The government’s official investigation by the Warren Commission reported that the president had been shot from behind. This confusion and weaknesses in the investigation led to an avalanche of conspiracy theories.