Dubica on 3 July. The main conspirators were tried in a military prison in Sarajevo. The state attorney charged twenty-two of the accused with high treason and first-degree murder and three with complicity to commit murder. The trial began on 12 October and lasted until 23 October. Čubrilović was only 17 years and six months old at the time. The Čubrilović brothers, Ivo Kranjčević and Neđo Kerović were defended by the lawyer Rudolf Zistler. At the trial, Čubrilović stated that the mistreatment of South Slavs by the Habsburgs motivated him to take part in the plot. "I can state that the monarchy is ruled by the Germans and the Magyars while the Slavs are oppressed," he said. Asked if he identified as a Serb or a Croat, Čubrilović declared himself a Serbo-Croat. "It means I don't consider myself solely a Serb," he explained, "but that I must work for Croatia as well as for Serbia." Though the trial ended on 23 October, sentencing did not occur until five days later. Čubrilović was convicted of treason and given a sixteen-year sentence. He had initially been sentenced to ten years' imprisonment. When asked his religious beliefs, he identified as an atheist, prompting the judges to add another three years. A further three were added after he refused to express remorse for the Archduke's death and blamed Austria-Hungary for starting the war. His brother Veljko was sentenced to death and hanged. Čubrilović was initially sent to serve out his sentence in Zenica prison. On 2 March, he and some of his co-conspirators were relocated to the Möllersdorf military prison, near Vienna. They were re-tried in Travnik on 14 June 1915, and had several years added to their sentences. Čubrilović was subsequently moved back to Möllersdorf. On 13 September 1917, the authorities decided to move almost all the surviving conspirators to Zenica prison. He remained imprisoned in Zenica until the end of the war. Interwar period Čubrilović completed his high school education in Sarajevo in 1919. First, he enrolled at the University of Zagreb to study history, but later transferred to the University of Belgrade, where he received a Bachelor's degree in history in 1922. In 1929, he obtained his Ph.D at the University of Belgrade with a thesis titled "The Bosnian Uprising 1875–1878". In the meantime, he had worked as a history teacher at high schools in Sremska Mitrovica, Sarajevo and Belgrade. The