GUATEMALA CITY, Ramadan 21, 1436, July 08, 2015, SPA -- Guatemala's forensic authority declared on Tuesday that ex-dictator Efrain Rios Montt is mentally unfit to be tried again on genocide charges, two years after a historic conviction of the former strongman was thrown out on a technicality, according to Reuters. The National Forensic Science Institute determined that due to cognitive deterioration the 89-year-old would not be able to defend himself against charges that he was responsible for the killings of nearly 2,000 indigenous Maya during a particularly brutal stretch of the country's 36-year civil war. Rios Montt's opponents accuse him of implementing a scorched earth policy, and his earlier conviction had been hailed as a landmark for justice in the Central American nation. The conflict claimed as many as 250,000 lives. "He does not have full use of his mental faculties and he is not capable of correctly understanding the charges against him," the institute said in a statement. The institute's conclusion was presented by lawyers representing Rios Montt, and the tribunal that handles the case must still decide whether or not to accept it at a hearing scheduled for July 23. Rios Montt was found guilty in May 2013 of overseeing the killings by the armed forces of at least 1,771 members of the Maya Ixil population during his 1982-83 rule. But the ex-general's 80-year jail sentence was thrown out less than two weeks later by the country's Constitutional Court citing procedural errors. --SPA 01:58 LOCAL TIME 22:58 GMT www.spa.gov.sa/w