Burke and Hare murders doctors, the Burkes and Hares were charged with murder. As part of his investigation Christison interviewed Knox, who asserted that Burke and Hare had watched poor lodging houses in Edinburgh and purchased bodies before anyone claimed them for burial. Christison thought Knox was "deficient in principle and heart", but did not think he had broken the law. Although the police were sure murder had taken place, and that at least one of the four was guilty, they were uncertain whether they could secure a conviction. Police also suspected there had been other murders committed, but the lack of bodies hampered
Whitechapel murders abandoned because the trail of scents was confused in the busy city, the dogs were inexperienced in an urban environment, and the owner Edwin Brough of Wyndyate near Scarborough (now Scalby Manor) was concerned that the dogs would be poisoned by criminals if their role in crime detection became known. On 27 September, the Central News Agency received a letter, dubbed the "Dear Boss" letter, in which the writer, who signed himself "Jack the Ripper", claimed to have committed the murders. On 1 October, a postcard, dubbed the "Saucy Jacky" postcard and also signed "Jack the Ripper", was received by