Source: 18th Battalion Nominal Roll, April 1915.
Find-A-Grave: Noted that he may have died on 6 March 1950 in London, England.
Family Search: When Lieutenant Walter John Carty was born on 4 May 1894, in Killarney, County Kerry, Ireland, his father, Patrick Carty, was 44 and his mother, Mrs. Annie Hogan, was 24. He lived in Galway, County Galway, Ireland for about 10 years. In 1911, at the age of 17, his occupation is listed as scholar in Galway, County Galway, Ireland. He died on 6 March 1950, in London, England, United Kingdom, at the age of 55.
Note that he is not listed at the LAC under his reg. no. But his name. His last name is misspelled in the Nominal Roll as Carthy, not Carty.
History of the 18th Battalion CEF, "The Fighting Eighteenth" 