On 10 June 1981, two robbers entered a municipal tax office at 56, Calle Fernando el Católico in Madrid, intending to make off with a large amount of money. They threatened the employees and managed to gather 300,000 pesetas, wounding one woman who was making a payment at the time. They then started to make their getaway.
Carlos Hernández Díaz, a 47-year-old municipal police officer from Madrid, tried to stop them, but the robbers shot him and he later died of his injuries. Carlos was married and had two children.
The killers were two brothers, Ángel and Carlos Pisonero Alonso, who were former members of GRAPO who had been thrown out of the terrorist group before the robbery took place. Since their expulsion in 1980, they had been holding up premises on their own account. In November they had taken 700,000 pesetas from another tax office in Madrid, on Calle Lérida.
A plaque has been erected at the site of Carlos Hernández’s killing. He was posthumously awarded the silver medal of Madrid by the then mayor of the city, Tierno Galván, and another silver medal for police merit by the civil governor, Mariano Nicolás.
In December 1981, six months after the robbery, one of the killers, Angel Pisonero, was shot several times by police as he was being arrested. He died in hospital four days later and was buried in the same cemetery in Carabanchel, where the victim of his robbery had been interred months before. His brother, Carlos Pisonero, was arrested in France and imprisoned from 1998 until 2009, when he was extradited to Spain to stand trial for the murder of Carlos Hernández Díaz.