Stowell claimed that his suspect had been incarcerated in a mental institution, when Albert Victor was serving in the British army, making regular public appearances, and visiting friends at country houses. Newspaper reports, Queen Victoria's diary, family letters, and official documents prove that Albert Victor was attending functions in public, or meeting foreign royalty, or hundreds of miles from London at the time of each of the five canonical murders. On 5 November 1970, Stowell wrote to The Times denying that it was his intention to imply Prince Albert Victor was Jack the Ripper. The letter was published on 9 November, the day after the elderly Stowell's own death from natural causes. The same week, Stowell's son reported that he had burned his father's papers, saying "I read just sufficient to make certain that there was nothing of importance." Claims of Joseph Gorman Though Stowell's hypothesis was incorrect, his article rekindled interest in the Jack the Ripper case, and in 1973 the BBC launched a television series, Jack the Ripper, which investigated the Whitechapel murders. The series mixed documentary and drama; it featured real evidence but was hosted by fictional detectives Barlow and Watt, played by Stratford Johns and Frank Windsor, respectively. The series was made into a book, The Ripper File, by Elwyn Jones and John Lloyd in 1975. The sixth and final programme included a testimony by Joseph Gorman, who called himself Joseph Sickert and claimed to be the illegitimate son of noted painter Walter Sickert. Gorman claimed that Sickert had told him a story that implicated not only the royal family but also a host of other famous people in the murders. According to Gorman, Gull committed the murders with the help of accomplices. Stowell had mentioned rumours implicating Gull in his article, but had dismissed them as unfair and false. Gorman said that his Catholic grandmother had secretly married Albert Victor, and that his mother, as the legitimate daughter of Albert Victor, was the rightful heir to the throne. He claimed that the Ripper murders were staged as part of a conspiracy to hush up any potential scandal by murdering anyone who knew of the birth. In the original television series, the story is depicted as the belief of Gorman but not of the detectives. Captivated by Gorman's story, journalist Stephen Knight decided to investigate the claims further, and eventually published his research as the book