Following the declaration of martial law in 1909 during the Tragic Week , he was arrested and , having been found guilty after a lengthy trial , executed by firing squad at Montjuich Fortress in Barcelona on 13 October .
When the martial law was reused in 1909 during the Tragic Week , he was arrested , convicted without any proof and executed by firing squad at Montjuich Fortress in Barcelona on 13 October .