MUNICH, Germany — John Demjanjuk, a 90-year-old on trial for assisting in the murder of nearly 30,000 Jews during World War II, lay on a hospital bed in a Munich courtroom with his eyes closed. In a neighboring room, a young Afghan man cradled his head in hands as his sister-in-law testified that he had killed his wife in a fit of jealousy. And in the hallway between those courtrooms, a gaggle of television cameras waited for the verdict in the trial of a teenager accused of perpetrating an act of random violence that had horrified the nation.