GULU, Uganda—On a Monday morning in March, dozens of people gathered outside the courthouse in this hot, dusty city in northern Uganda. They sipped passion fruit juice as they prepared to watch legal proceedings projected on a canvas screen, which had been set up in the shade.

Inside and up three flights of stairs, journalists and representatives of various development organizations pressed together on wooden benches in the courtroom. Lawyers, dressed in black robes, made small talk, though their easy laughter clashed with the gravity of the matter at hand. The trial of Thomas Kwoyelo was about to begin.