Fifty years ago today, in the wee hours of the morning, then-senator Robert F. Kennedy – presidential candidate, younger brother of President John F. Kennedy, was shot. Gerard Doherty was and is a close Kennedy family friend. Now 90 years old and living in the house where he was born in Charlestown, he recalls his first youthful encounter with the Kennedy family. It was June, 1946. Doherty had just graduated from high school and was Harvard-bound. Charlestown was hopping: it was the Bunker Hill Day parade, and local candidates were there, drumming up votes. He remembers his dad chatting up a group of campaigners.

Doherty: They were headed by this very, very skinny guy. My father gave them lemonade. So he started to chat about how I was going to Harvard, and he knew the fellow had gone to Harvard. The fellow shook my hand and said ‘good luck’ and ‘my name is John Kennedy.'

It was the start of a relationship that would span decades. Kennedy won his congressional seat that fall. Later, after Doherty graduated from Harvard, he helped with John Kennedy's senate campaigns in the 1950's. Then in 1962, he was on board for Ted Kennedy's senate run. A year later, in 1963, President Kennedy was assassinated. His younger brother Robert had served him as attorney general, and stayed on for a year under the new president, Lyndon Johnson. Then Robert himself was elected senator from New York, and four years later, in the winter of 1968, he mounted a late bid to unseat President Johnson. His first primary state: Indiana. Doherty was again tapped, asked to manage the campaign there. And Doherty knew it would not be easy for Robert Kennedy, because it hadn't been easy for his brother.

Doherty: John Kennedy lost Indiana by 200-thousand votes, and it's not a very friendly place.

Meantime, Johnson dropped out of the race. But Robert Kennedy still faced competition in the primary. First, Doherty had to collect enough signatures just to get Kennedy on Indiana's primary ballot. Some were doubtful.

Doherty: They said it couldn’t be done, and I said, you know, I’m not Mickey Mouse, but we’re getting the signatures.

Doherty knew that African-Americans would be key to getting Kennedy on that ballot. He says a little luck – and a tie to Boston – came into play. While campaigning in Indianapolis, Doherty says he happened upon some black students in their band uniforms emblazoned with the name of their high school: Crispus Attucks, the black patriot killed at the Boston Massacre of 1770. Citing that Boston connection, Doherty asked for help.

Doherty: I called the principal and he got me these kids to stand in their uniform outside of seven black churches, and we ended up getting enough signatures to get on the ballot.

Kennedy started barnstorming the state. On April 4th, he was flying into Indianapolis and got word that Martin Luther King Jr. had been killed. The crowd, many from inner-city Indianapolis, had gathered that night unaware, expecting a rousing campaign speech as Kennedy climbed up onto the back of a flatbed truck. Kennedy hushed the crowd, many about to hear the news for the first time.

Kennedy: I have some very sad news for all of you, and I think sad news for all of our fellow citizens, and people who love peace all over the world. And that is that Martin Luther King was shot and was killed tonight in Memphis, Tennessee.

Kennedy continued in what is considered to be one of his most powerful speeches, calling for unity. Doherty, who was there, says he remembers Kennedy touching a nerve as his words got personal.

Kennedy: I had a member of my family killed, but he was killed by a white man. But we have to make an effort in the United States. We have to make an effort to understand, to get beyond or go beyond these rather difficult times.

Kennedy's speech is widely credited with diffusing tensions in Indianapolis, while there was violence elsewhere across America that night. Kennedy did go on, and with African-American voters putting him over the top, won the Indiana primary. Doherty says Kennedy told him that he was grateful.

Doherty: He got very moved and he said, 'what you did for me, you've proven that you're one of my greatest friends.'

A week after Indiana, Kennedy won Nebraska. Then, after a loss in Oregon, he had a big win in California. And there, shortly after midnight, the morning of June 5th 1968, Robert Kennedy delivered a victory speech at the Ambassador Hotel in Los Angeles. Shortly after leaving the stage, shots rang out.

Andrew West, Mutual Broadcasting System: Senator Kennedy has been shot. Is that possible? Is that possible? It's been…is it possible ladies and gentlemen? It is possible he has been shot. Not only Senator Kennedy. Oh my God. Senator Kennedy has been shot.

Kennedy was rushed to the hospital. Doctors worked to keep him alive, but the following day, Robert F. Kennedy, age 42, was dead. It had been exactly nine weeks to the day since he'd stood on that flatbed truck back in Indianapolis and spoke tenderly of Martin Luther King Jr. to a grief-stricken crowd. The final words of that speech still resonate today.

Kennedy: We've had difficult times in the past, and we will have difficult times in the future. It is not the end of violence. It is not the end of lawlessness, and it's not the end of disorder. But the vast majority of white people and the vast majority of black people in this country want to live together, want to improve the quality of our life, and want justice for all human beings that abide in our land. To dedicate ourselves to what the Greeks wrote so many years ago, to tame the savageness of man and make gentle the life of this world. Let us dedicate ourselves to that, and say a prayer for our country and for our people. Thank you very much.

This article has been updated.