Before the killers were captured, author Truman Capote learned of the Clutter family murders and decided to travel to Kansas and write about the crime. He was accompanied by his childhood friend and fellow author, Harper Lee. Together, they interviewed local residents and investigators assigned to the case and took thousands of pages of notes. The killers, Hickock and Smith, were arrested six weeks after the murders and were eventually executed by the state of Kansas in 1965. Capote ultimately spent six years working on his book. When finally published in 1966, "In Cold Blood" was an instant success. Today, it is the second-best-selling true crime book in publishing history, behind Vincent Bugliosi's 1974 book "Helter Skelter", about the Charles Manson murders.