The Justice Department can appeal the ruling. But legal experts said it will have a difficult time because Urbina wrote such a detailed opinion and held such long hearings. Prosecutors can also seek a fresh indictment but would be precluded from using any evidence that Urbina ruled was tainted. That would be another tough task because Urbina eviscerated much of the government's case. He also found that many of its key witnesses were badly tainted by the guards' statements, which they had read or heard about in the news media.