work. 2019 Louhelainen study Louhelainen's 2014 findings were criticised as they had not been subject to peer review by other scientists or investigators. In March 2019, the Journal of Forensic Sciences published a study analysing the mitochondrial DNA from cells extracted from a shawl claimed to have been found near the body of victim Catherine Eddowes, as well as samples from maternal relations of the victim and suspect (Kosminski). This study, conducted by scientists at Liverpool John Moores University and the University of Leeds, stated in its conclusion that "the presence of mtDNA on the shawl matches the female victim's mtDNA derived from stains on it and that mtDNA also on the shawl matches the suspect candidate's mtDNA"; however, Figure 7 of the same paper shows two differences between the suspect candidate's mtDNA sequence and the sequence obtained from the shawl, and in their conclusion the authors state, "According to the SWGDAM 2013 guidelines, if samples have two or more nucleotide position differences, they can be excluded as coming from the same source or maternal lineage, except when heteroplasmy is encountered." There is no suggestion that heteroplasmy is present. Kosminski and "David Cohen" Another Polish Jew proposed as a suspect in the Jack the Ripper murders was Aaron Davis Cohen or David Cohen, whose incarceration at Colney Hatch Lunatic Asylum roughly coincided with the end of the murders. He was committed on 12 December 1888, about one month after the murder of Mary Jane Kelly on 9 November. He was described as violently antisocial, exhibited destructive tendencies while at the asylum, and had to be restrained. He was the same age as Kosminski, and died at the asylum in October 1889. Author Martin Fido suggested in his book The Crimes, Detection and Death of Jack the Ripper (1987) that the name "David Cohen" was used by the asylum as a simple name for an inmate whose true name (Kosminski or Kaminsky) was too difficult to spell or easily misunderstood. Fido identified Cohen with "Leather Apron", a Polish Jewish bootmaker blamed for the murders in local gossip, and speculated that Cohen's true identity was Nathan Kaminsky, a bootmaker living in Whitechapel who had been treated at one time for syphilis. Fido was unable to trace Kaminsky after May 1888, and records of Cohen began that December. Fido suggested that police officials confused the name Kaminsky with Kosminski, resulting in the wrong