On October 19th…

October 19, 1889: The Red-Headed League was dissolved. [REDH]
October 19, 1889: Holmes captured John Clay. [REDH]
October 19, 1900: Holmes and Watson shot and killed the Hound of the Baskervilles. [HOUN]
October 19, 1900: Jack Stapleton perished in the Grimpen Mire