Kennedy had served as United States Attorney General from January 1961 until September 3, 1964, first in the cabinet of his brother President John F. Kennedy and then briefly under his nemesis Lyndon Johnson. He resigned to run for election to the United States Senate in New York, winning that election and being sworn in as Senator from New York on January 3, 1965. The approach of the 1968 presidential election saw the incumbent president Lyndon Johnson losing popularity during a period of civil unrest. There were riots in the major cities despite Johnson's attempts to introduce anti-poverty and anti-discrimination legislation, and there was significant opposition to the ongoing Vietnam War. The assassination of Martin Luther King, Jr. in April 1968 led to further riots in 100 cities.
Kennedy entered the race for the Democratic Party's nomination for president on March 16, 1968, four days after Senator Eugene McCarthy, a candidate opposed to the war in Vietnam, received a large percentage of the vote in the New Hampshire primary against the incumbent President (42% to Johnson's 49%). Two weeks later, a demoralized Johnson announced he was no longer seeking re-election. One month later, Vice President Hubert Humphrey announced he would seek the presidency.
The 1968 California Primary took place on Tuesday, June 4. Four hours after the polls closed in California, Kennedy was declared the winner. At approximately 12:10 a.m. PDT, he addressed his campaign supporters in the Ambassador Hotel's Embassy Room ballroom. The government provided Secret Service protection for incumbent presidents but not for presidential candidates. Kennedy's only security was provided by former FBI agent William Barry and two unofficial bodyguards, former professional athletes Roosevelt Grier and Rafer Johnson. During the campaign, Kennedy had welcomed contact with the public.
Kennedy had planned to walk through the ballroom when he had finished speaking, on his way to another gathering of supporters elsewhere in the hotel.But Campaign aide Fred Dutton decided that Kennedy would forgo the second gathering and instead go through the kitchen and pantry area behind the ballroom to the press area. Kennedy finished speaking and started to exit when William Barry stopped him and said, "No, it's been changed. We're going this way." Barry and Dutton began clearing a way for Kennedy to go left through swinging doors to the kitchen corridor, but Kennedy, hemmed in by the crowd, followed maître d'hôtel Karl Uecker through a back exit.
Uecker led Kennedy through the kitchen area, holding Kennedy's right wrist but frequently releasing it as Kennedy shook hands with those he encountered. Uecker and Kennedy started down a passageway narrowed by an ice machine against the right wall and a steam table to the left. Kennedy turned to his left and shook hands with busboy Juan Romero. Sirhan Sirhan, a Palestinian with strong anti-Zionist beliefs, stepped down from a low tray-stacker beside the ice machine, rushed past Uecker, and repeatedly fired a .22 caliber Iver-Johnson Cadet revolver.
Kennedy fell to the floor and security man Bill Barry saw Sirhan holding a gun and hit him twice in the face while others, including maîtres d' Uecker and Edward Minasian, writer George Plimpton, Olympic gold medal decathlete Rafer Johnson and professional football player Rosey Grier, forced Sirhan against the steam table and disarmed him as he continued firing his gun in random directions. After a minute, Sirhan wrestled free and grabbed the revolver again, but he had already fired all the bullets. He was once again restrained.
Barry went to Kennedy and laid his jacket under the candidate's head, later recalling: "I knew immediately it was a .22, a small caliber, so I hoped it wouldn't be so bad, but then I saw the hole in the Senator's head, and I knew". Reporters and photographers rushed into the area from both directions, contributing to the confusion and chaos. As Kennedy lay wounded, Juan Romero cradled the senator's head and placed a rosary in his hand. Kennedy asked Romero, "Is everybody safe, OK?" and Romero responded, "Yes, yes, everything is going to be OK". The image was captured by Life photographer Bill Eppridge and Boris Yaro of the Los Angeles Times.
Ethel Kennedy stood outside the crush of people at the scene, but was soon led to her husband and knelt beside him. After several minutes, medical attendants arrived and lifted Kennedy onto a stretcher, prompting him to whisper, "Don't lift me". He lost consciousness shortly thereafter. Kennedy was taken a mile away to Central Receiving Hospital, where he arrived near death. One doctor slapped his face, calling, "Bob, Bob", while another massaged Kennedy's heart. After obtaining a good heartbeat, doctors handed a stethoscope to Ethel Kennedy so she could hear her husband's heart beating. After about 30 minutes, Kennedy was transferred several blocks to the Hospital of the Good Samaritan for surgery. Surgery began at 3:12 a.m. PDT and lasted three hours and 40 minutes.
Ten and a half hours later, at 5:30 p.m. PDT on Wednesday, spokesman Frank Mankiewicz announced that Kennedy's doctors were "concerned over his continuing failure to show improvement". Kennedy had been shot three times. One bullet, fired at a range of about 1 inch, entered behind his right ear, dispersing fragments throughout his brain. Two others entered at the rear of his right armpit; one exited from his chest and the other lodged in the back of his neck.
Despite extensive neurosurgery at the Good Samaritan Hospital to remove the bullet and bone fragments from his brain, Kennedy died at 1:44 a.m. PDT on June 6, nearly 26 hours after the shooting.
Five other people were also wounded: William Weisel of ABC News, Paul Schrade of the United Auto Workers union, Democratic Party activist Elizabeth Evans, Ira Goldstein of the Continental News Service and Kennedy campaign volunteer Irwin Stroll.
Following the California primary, Kennedy was in second place with 393 delegates compared to 561 for Vice-President Hubert Humphrey. Following is a YouTube video of Robert Kennedy's final remarks to the crowd at the Ambassador Hotel on June 5, 1968, followed by news coverage of the assassination: