abuja trial 1,600 people suspect tie boko haram expect begin nigeria monday behind close doors big legal investigation eight-year militant islamist insurgency 20,000 people kill two million force home northeastern nigeria insurgency contribute unite nations say among world bad humanitarian crises nigeria ministry justice say last month trial around 1,670 people hold kainji detention facility would begin site central niger state monday would preside four judge spokesman ministry respond request confirmation trial begin military spokesman decline comment say question address judiciary ministry say kainji trials complete 651 people suspect link boko haram currently hold prisons maiduguri capital northeastern state borno would go trial clement nwankwo human right lawyer base capital abuja say trials would provide effective deterrent open media public boko haram issue stories need tell public make aware go understand nature crimes commit say nwankwo add secrecy also make hard determine whether trials fair nigerian authorities know diligent investigate properly prosecute suspect say warn sense injustice could breed resentment among relatives could yield future radicalization however fatima akilu head government counter violent extremism program previous administration say secrecy need encourage witness judge take part trials nigeria witness protection program lot witness afraid come forward akilu base office national security adviser 2012 2015 say previous efforts pursue trials say judge witness previously subject death threats witness come forward limit evidence term reach conviction think little choice say add clear alternatives absence amnesty program nigeria handle thousands people accuse tie boko haram insurgents previously attract criticism legal process mark steep escalation number insurgency-related case handle nigerian authorities ministry justice say sept. 11 13 terrorism case conclude nine convictions secure decision start trials response persistent complaints local international human right group thousands persons detain without access lawyers without specific charge say nnamdi obasi international crisis group nigeria set start mass trial boko haram suspect behind close doors