Former U.S.-backed Guatemalan dictator Efraín Ríos Montt has spent his first days in prison after being convicted of genocide. On Friday, a three-judge panel found Ríos Montt guilty of overseeing the slaughter of more than 1,700 people in Guatemala’s Ixil region after seizing power in 1982. The conviction marked the first time a former head of state has been found guilty of genocide in his or her own country. During the two-month trial, nearly 100 witnesses testified of massacres, torture and rape by state forces. Many wept and cheered in celebration after the verdict was read. The judge in the case has instructed prosecutors to launch an immediate investigation of “all others” connected to the crimes. Guatemalan President Otto Pérez Molina was among those implicated during the trial’s testimony. Pérez Molina served as a regional commander under Ríos Montt using a different name. In an interview with CNN, Pérez Molina denied that a genocide ever occurred and said he would support Ríos Montt’s appeal.