sentences:  Knight's conspiracy theory originated from the story of Joseph Sickert, who claimed to be the illegitimate son of Walter Sickert, another 'Ripper' suspect.He related that after the killings had concluded, Netley was heavily involved in attempts on the life of the young Alice Crook (supposedly the illegitimate daughter of Annie Crook and Prince Albert Victor, Duke of Clarence and Avondale, the grandson of Queen Victoria), trying to run her down with his carriage.Joseph Sickert claimed that he drowned after the attempt, having run to Westminster where he jumped off the pier.