Kainji - The prosecution only called one witness against Abba Umar. He said the defendant, if released, would likely go back to Boko Haram's hideout in Sambisa Forest in northeast Nigeria.But Umar had already done himself no favours. He had pleaded not guilty yet described himself as an "Islamic warrior" and a "commander of the Islamic army".Curious faces peered around the door or through the window to catch a glimpse of the defendant, who like the hundreds of others was barefoot and wearing orange overalls.Seemingly inevitably, the judge found him guilty and sentenced him to five lengthy jail terms, to run concurrently:- Seven years for failing to disclose information about Boko Haram leader Abubakar Shekau; - 15 years for being a Boko Haram member; - 15 years for receiving terrorism training; - 30 years for involvement in a failed suicide car bomb attack on a secondary school in Gombe state.- 60 years for taking part in a series of deadly attacks in Borno state.KEEP UPDATED on the latest news from around the continent by subscribing to our FREE newsletter, Hello Africa.FOLLOW News24 Africa on Twitter and Facebook. "I would have been more merciful but was dissuaded by the convict's insistence that he would go back to the activities which constitute a danger to society and for which he was apprehended," the judge added.Umar, who was arrested in 2014 aged just 18, remained impassive and even rejected an offer to plead for leniency."I have already said all I have to say," he told the court. "I have nothing to say again."With that, he was taken away. Opening up Boko Haram's bloody quest to establish a hardline Islamic state in remote northeast Nigeria over the last nine years has its own grim accounting.At least 20 000 have been killed and more than 2.6 million others made homeless by violence that has spilled across the border into Cameroon, Chad and Niger.Now, 1 669 other people can be added to the list of statistics.They comprise the men, but also some women and children, who were arrested as Boko Haram suspects.Nigeria was widely criticised for holding them and thousands of other civilians for years without even a sight of a lawyer or a courtroom. Held at the Kainji barracks in central Niger state, their cases finally began last October, initially behind closed doors at four specially-constituted civilian courts at the army facility.This week, access restrictions were lifted and the media and public got a rare first glimpse of those being held - and the charges against them.On Monday, defendants included Haruna Yahaya, who was jailed for 15 years for involvement in the kidnapping of more than 200 schoolgirls from the town of Chibok in 2014.The 35-year-old disabled former trader, who said he was forced to fight for the jihadists, was one of 20 people convicted and sentenced on Monday. Umar was one of 42 cases dealt with on Tuesday.Some, like Mohammed Hussain, identified as a Boko Haram commander, pleaded guilty to involvement in attacks in Yobe and Borno states. He was jailed for 20 years.Last October, he said he had no regrets."If I die today, I am fulfilled and I know I will go straight to heaven because I have done my bit of what Allah wants me to do, which is to kill the kafirs (unbelievers) in our midst," he was reported as saying.Swift justice Questions have been raised about the ability of Nigeria's over-burdened justice system to cope with so many defendants, and the standard of investigations and evidence.The government has said 468 people were released after it was found they had no case to answer; 45 were jailed for between two and 15 years; 28 had their cases transferred.A further 82 pleaded guilty in exchange for a lesser prison sentence or release, taking into account time served in custody.The remaining detainees waiting to hear their fate were brought out of detention to sit outside the courtrooms under canopies until their cases were called.Lawyers from the Legal Aid Council of Nigeria were on hand to prepare their defence.Those that trooped into the two-storey administrative block where the courts were set up were out again within 30 minutes or two hours, depending on their plea.Some, like Ahmad Mustapha, who admitted concealing information from the authorities about Boko Haram suspects, were among the luckier ones.The judge discharged his case and ordered the government to get him medical treatment for the stroke that has paralysed his left leg and hand.How long the process will last is anyone's guess, admitted one prosecutor. But even then, there are more cases to be heard elsewhere."Our next port of call, after we are finally done with Kainji, is Maiduguri, where we have about 4,000 suspects waiting," said the lawyer.