More than any love for Dr. King, then, it was the promise he’d made to black Indianapolis — his core constituency in the upcoming state primary — and probably the very danger of the mission that brought Kennedy to 17th and Broadway that night. But once there, he embraced Dr. King more passionately than he ever had in life.

He arrived late, by which time things had grown darker, colder, rainier, angrier: many in the crowd, especially more recent arrivals, already knew Dr. King was gone. Some taunted whites there; others, gang members, were bent on violence. “They kill Martin Luther, and we was ready to move,” one later said.

Draped in his brother’s old overcoat, Kennedy climbed the rickety steps leading to the back of a pickup truck that would serve that night as his podium. “This little bitty, small white man started talking, and you could see it was Robert Kennedy,” Darlene Howard, who lived in the neighborhood, later told the filmmaker Donald Boggs. “And I thought, ‘Oh, my God, they’re going to kill him.’ ” Nearby, one of Kennedy’s advance men, Jerry Bruno, eyed the crowd apprehensively, as well he might: He’d been on duty in Dallas when President Kennedy was killed.

“I have some very sad news for all of you,” Kennedy began, before making his grim announcement. He then described how Dr. King had dedicated his life to love and to justice, and he pleaded for the love and understanding for which Dr. King had always stood. Then he said something startling. “For those of you who are black and are tempted to be filled with hatred and mistrust of the injustice of such an act against all white people, I would only say that I can also feel in my own heart the same kind of feeling,” he said. “I had a member of my own family killed, but he was killed by a white man.”

Everyone knew that already, of course, but it was something Robert Kennedy had never mentioned publicly before, and it seemed to leach out any remaining venom in the crowd. “After he spoke we couldn’t get nowhere,” a gang member later told Karl Anatol and John Bittner of Purdue University.

Kennedy then cited some lines from Aeschylus’ “Agamemnon.” Whether it was strangely tone deaf or the ultimate in respect to do so in such a setting really didn’t matter; words like “pain,” “heart,” “despair,” “awful,” “grace” and “God” resonated in black Indianapolis. “So I ask you tonight to return home, to say a prayer for the family of Martin Luther King, but more importantly to say a prayer for our own country, which all of us love,” he concluded. All told, he spoke that night for around six minutes. But unlike so many other American cities, Indianapolis didn’t burn that night or over the next few days, as did Washington, Chicago, Baltimore and scores of other American cities.