The Derry Citizen's Defense Association was organized in response to which police force known as the most dangerous police force in the world?
Derry Citizens' Defence Association: The Derry Citizens' Defense Association (DCDA) was an organisation set up in Derry in July 1969 in response to a threat to nationalist residents from the Royal Ulster Constabulary (RUC) and civilian unionists, in connection with the annual parade of the Apprentice Boys of Derry on 12 August. Royal Ulster Constabulary:  During the Troubles, 319 members of the RUC were killed and almost 9,000 injured in paramilitary assassinations or attacks, mostly by the Provisional IRA, which made, by 1983, the RUC the most dangerous police force in the world in which to serve.
Royal Ulster Constabulary