Park's popularity in South Korea declined during the 1970s, as the economic growth of the 1960s began to slow and the public became more critical of his authoritarianism. On 26 October 1979, Park was assassinated at a safehouse by Kim Jae-gyu, the director of the Korean Central Intelligence Agency (KCIA), causing political turmoil in South Korea. Park's successor, Choi Kyu-hah, was an ineffective president whose authority was largely ignored by the political elite. In December, Major General Chun Doo-hwan, the Chairman of the Defense Security Command and a former military colleague of Park, overthrew Choi's government in the Coup d'état of December Twelfth, and over the next few months gained control over most government apparatuses. In May 1980, Chun launched the Coup d'état of May Seventeenth establishing a military dictatorship under National Council for Reunification and declared martial law. Chun violently suppressed the subsequent Gwangju Uprising democracy movement against his rule in Gwangju, during which 200-600 people may have died. In August, Choi resigned and Chun was elected President in the 1980 presidential election by the National Council, running unopposed and winning 99.37% of the vote. In October, Chun abolished all political parties and established his own, the Democratic Justice Party, which was effectively a re-branding of Park's Democratic Republican Party that ruled South Korea since 1963. Soon afterwards, a new constitution was enacted that, while far less authoritarian than Park's Yusin Constitution, still gave fairly broad powers to the president.