The 20th anniversary of 9/11 reminded Americans of how one attack on the homeland can change the course of history. But another reminder came just a month earlier, when a California parole board recommended the release of the man responsible for the first real act of Middle Eastern terrorism against America.

Just after midnight on June 5, 1968, Sirhan Bishara Sirhan gunned down Robert F. Kennedy in the crowded kitchen of the Ambassador Hotel in Los Angeles, moments after the charismatic New York senator had claimed victory in California’s Democratic presidential primary. It was one of the most traumatizing political assassinations in modern U.S. history, and it left hundreds of thousands of Americans reeling with grief. In the wake of Martin Luther King Jr.’s murder in Memphis just two months earlier, many feared that the nation was coming apart at the seams — that the world’s democratic superpower was on the verge of something “like a mental breakdown,” as Hubert Humphrey later expressed it.