Four hours after the polls closed in California, Kennedy claimed victory in the state's Democratic presidential primary. At approximately 12:15 a.m. PDT, he addressed his campaign supporters in the Ambassador Hotel's Embassy Room ballroom, in the Mid-Wilshire district of Los Angeles. At the time, 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. During the campaign, Kennedy had welcomed contact with the public, and people had often tried to touch him in their excitement.
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. However, with deadlines fast approaching, reporters wanted a press conference. 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 hotel maître d' 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 as Sirhan Sirhan stepped down from a low tray-stacker beside the ice machine, rushed past Uecker, and repeatedly fired what was later identified as a .22 caliber Iver-Johnson Cadet revolver.