Following the election, Socialist deputy Giacomo Matteotti was assassinated after calling for an annulment of the elections because of the irregularities. Following the assassination, the Socialists walked out of parliament, allowing Mussolini to pass more authoritarian laws. In 1925, Mussolini accepted responsibility for the Fascist violence in 1924 and promised that dissenters would be dealt with harshly. Before the speech, Blackshirts smashed opposition presses and beat up several of Mussolini's opponents. This event is considered the onset of undisguised Fascist dictatorship in Italy, though it would be 1928 before the Fascist Party was formally declared the only legal party in the country.