Many members of the officer corps willingly accepted the prospect of a transition to a new constitutional order, but others, mainly in the army, who still identified with Franco's ideological notions, regarded democratisation as a betrayal of the nationalist victory in the civil war that ended in 1939.
[1][2] The existence of the organisation quickly became known to the SECED, the intelligence service of the Spanish state, and nine of its members were arrested in Madrid in July 1975, put on trial and condemned in 1976 to prison sentences of up to eight years.
Notably, one of the arrested members of UMD had been born inside the citadel of Alcázar during its protracted siege by Republican forces, in the Spanish Civil War.
[4] The investigation caused political turmoil, with people opposed to it claiming that the 1977 amnesty covered all the crimes committed by either side during the Civil War.
[4] One of the founding members of UDM, retired colonel Julián Delgado, who, after the transition to democracy, was appointed head of the Guardia Urbana (the city police force) in Barcelona, publicly objected to the investigation, because it would be "absurd to stir up pain.