When the Spanish Civil War broke out in 1936-1939, he joined the side of the rebels and in May 1937 he was appointed by Francisco Franco as Head of Security at the Generalist Headquarters in Salamanca.

[2] The new Republican Town Hall of Gijón, constituted after the municipal elections of 12 April 1931, tried to start a process of purging the responsibilities for the actions carried out by Captain Doval and the Civil Guards under his orders.

When Doval found out about the City Council's intentions, he wrote a long exculpatory letter that was published in the newspapers El Comercio and La Prensa.

The following day, several letters appeared in the newspaper El Noroeste to the director of lawyers and people detained by Doval, in which they denounced the torture and ill-treatment they had been subjected to or had become aware of.

Among them were the city's mayor, Casto Prieto Carrasco, professor of radiology at the Faculty of Medicine of the University of Salamanca, and the socialist deputy José Andrés Manso.