Dr. William Evan Thomas
Thomas was a doctor, who after suffering a nervous breakdown, committed suicide on 21 June 1889 by taking a large quantity of poison. Thomas was born on the Isle of Anglesey in North Wales in 1856, the son of a local pharmacist. He had a surgery at 190 Green Street, Victoria Park, some distance from where the Whitechapel murders occurred. Thomas, however, did reside in London at the time of the murders and would have had the requisite medical skills, though did not commit suicide shortly after the murder of Mary Kelly as claimed, but some seven months later. Apart from his suicide, there is nothing to connect him to Jack the Ripper. Thomas fits the criteria for those seeking a suspect with the requisite medical knowledge and who's suicide, due to mental instability, coincided with the ending of the murders.
