In 1962, Quinn became a general assignment television reporter for NBC News. He covered mayor political and social stories of the 1960s, including presidential campaigns, the civil rights movement, along with news film editor Donald Swerdlow. as well as protests against the Vietnam War. Quinn was present at the Ambassador Hotel in Los Angeles, covering United States Senator Robert F. Kennedy's 1968 presidential campaign, on the night he was assassinated. He was one of the first reporters to arrive at the scene of the shooting, telling television viewers, "He's lying here on the floor. Senator Kennedy has been shot. He's been shot...There’s blood on the floor."