José del Castillo Sáez de Tejada (29 June 1901 – 12 July 1936) was a Spanish Police Guardia de Asalto (Assault Guard) lieutenant during the Second Spanish Republic. His murder by four Falangist gunmen on 12 July 1936 led to a sequence of events that helped precipitate the Spanish Civil War. Early life and military career José Castillo was the son of a lawyer of liberal political views. His mother came from an aristocratic family and was distantly related to General Miguel Primo de Rivera (Spanish dictator 1923–30). After attending school in Granada, Castillo entered the Infantry Officers' Academy in Toledo, in 1919. After graduation he became a junior officer in the 1st Regulares (Moroccan colonial troops). He saw active service in the Rif War, rising to the rank of Lieutenant. In 1925 he transferred to a Peninsular regiment of regular infantry, Under the Republic Following the overthrow of the Monarchy in 1931, José Castillo was appointed to the newly raised Assault Guards, a para-military force intended to maintain security in urban areas and provide a counterweight to the long established and conservative Guardia Civil. Officers of the Asaltos were selected for their perceived loyalty to the new Republic. Castillo had partaken in the failed rebellion of October 1934. Castillo was a member of the Union Militar Republicana Antifascista (UMRA), an anti-fascist organization for military members, and also worked in training the militia of the socialist youth. In April 1936, he commanded the Assault Guard unit which forcibly put down the riots that broke out at the funeral of Guardia Civil lieutenant Anastasio de los Reyes; for this, he was marked for death by the Falange. (The Guardia de Asalto were generally in favor of the Republic, the Guardia Civil more connected to what was to become the insurrectionary right-wing opposition.) Assassination Castillo had been placed on a Falangist blacklist after he was incorrectly blamed for the death of José Antonio Primo de Rivera's cousin, Andrés Sáez de Heredia. Heredia had been killed during shootouts during the funeral procession of the Civil Guard officer Anastasio de los Reyes, who had been killed in unclear circumstances during a military parade on April 14. While Reyes had no known political views, the Spanish left-wing blamed his killing on fascists, while the Spanish right-wing claimed him as one of their own and held a large funeral for him as a political demonstration against