Bangladesh on Monday charged 824 people for the massacre of scores of senior army officers during a mutiny in February last year that briefly threatened the government, a state prosecutor said. 'We have charged 824 people with murder, conspiracy, aiding and abetting murder, looting military weapons and arson,' state prosecutor Mosharraf Hossain Kazal told selfnews, adding the trial would take at least one year to complete. Seventy-four people, including 57 senior army officers, were killed in a 33-hour siege at a military base in the capital Dhaka that was the first major crisis for the newly elected government of Prime Minister Sheikh Hasina. All of the accused, who are being tried in Bangladesh's civil courts, have been charged with murder and could face the death penalty, Kazal said. Police investigators on the civil case, which is the country's single largest criminal probe, have interviewed 9,500 border guards and civilians and have detained 2,307 people suspected of involvement. The killings were pre-planned, leading police investigator Abdul Kahhar Akhand told selfnews, and stemmed from pent-up anger among Bangladeshi Rifles (BDR) soldiers over their superiors' refusal to increase their pay and improve working conditions. 'They mowed their officers down in cold blood, using semi-automatic weapons and rifles they'd looted from the barracks,' Akhand said of the mutineers, who took over the BDR headquarters on February 25, 2009. The mutineers hid the bodies of dead army officers in shallow graves and sewers before escaping in civilian clothes. In parallel prosecutions, an estimated 3,500 soldiers who joined the mutiny as it spread to some 40 border posts across the country are being tried in special military courts, which were set up by the BDR, on lesser charges. At least 200 guards have already been sentenced in these special military courts, which do not provide defendants with lawyers, to sentences ranging from one month to seven years in prison. The sentences cannot be appealed. The criminal charges announced Monday are for more serious charges and for those directly implicated in the killing, looting, torture and overall planning of the mutiny. 