In Kosminski's defence, he was described as harmless in the asylum. He had originally been taken into custody for threatening either his sister or the sister of a witness to his admittance with a knife, and brandished a chair at an asylum attendant in January 1892, but these two incidents are the only known indications of violent behaviour. In the asylum, Kosminski preferred to speak his native language, Yiddish, which indicates that his English may have been poor, and that he was unable to persuade English-speaking victims into dark alleyways, as the Ripper was supposed to do. However, the "canonical five" killings that are most frequently blamed on the Ripper concluded in 1888; Kosminski's movements were not restricted until 1891. DNA evidence claims 2014 Louhelainen study On 7 September 2014, Jari Louhelainen, an expert in historic DNA analysis, announced that he had been commissioned by British author Russell Edwards to study a shawl said to have been found with victim Catherine Eddowes and that he had extracted mitochondrial DNA that matches female line descendants of Eddowes, and mitochondrial DNA that matches female line descendants of Kosminski's sister from the shawl. Louhelainen stated: "The first strand of DNA showed a 99.2 percent match, as the analysis instrument could not determine the sequence of the missing 0.8 percent fragment of DNA. On testing the second strand, we achieved a perfect 100 percent match." In his book Naming Jack The Ripper, Edwards names Kosminski as Jack the Ripper. Edwards was inspired to try to solve the case after the release of From Hell, the 2001 Johnny Depp film about the Whitechapel murders. He bought the shawl at auction and commissioned Louhelainen, with Dr. David Miller assisting, to analyse it for forensic DNA evidence. Edwards states that Kosminski was on a list of police suspects but there was never enough evidence to bring him to trial at the time. Kosminski died at the age of 53 of gangrene of the leg in a London mental hospital in 1919. He said that the DNA samples proved that Kosminski was "definitely, categorically and absolutely" the person responsible for the Whitechapel murders committed by Jack the Ripper. He told The Independent, "I've got the only piece of forensic evidence in the whole history of the case." He continued, "I've spent 14 years working on it, and we have definitively solved the mystery of who Jack the Ripper