The narrator shares that the hostages genuinely don’t know what happened between when the robber freed them and when the police stormed the apartment. But once the robber was gone, the special negotiator from Stockholm called the robber to try to come to an agreement. The robber didn’t answer, though—and a shot rang out in the apartment. When the police stormed the apartment, they discovered puddles of blood.
Readers, it seems, won’t learn much more than the hostages for now; indeed, this scene asks more questions than it answers. However, assuming the robber did turn the gun on themselves, and this is where the blood came from, this creates more tension—an already serious situation just got even more dire.