Ethiopia's Supreme Court on Monday sentenced exiled former leader Mengistu Haile Mariam to death in absentia for presiding over a 17-year rule that saw tens of thousands tortured and killed. The BBC reported that the court overturned a 2007 High Court ruling that sentenced Mengistu and 18 of his senior aides to life imprisonment. The presiding judge said that the actions of Mengistu and his aides during his reign amounted to genocide. Mengistu came to power in 1974 after toppling Haile Selassie, Ethiopia's last emperor. Mengistu fled to Zimbabwe in 1991 as rebel forces closed in. He has remained there under the protection of his ally President Robert Mugabe. Zimbabwe refused to extradite Mengistu following the original life sentence in 2007.