On the morning of December 31st, 2000, Setsuko Miyazawa walked into her son’s home in Tokyo—only to uncover one of Japan’s most horrifying crime scenes. Her entire family — Mikio, Yasuko, and their two children — had been brutally murdered. What followed shocked investigators: the killer didn’t flee. Instead, he stayed for hours, eating ice cream, using their computer, and even leaving unflushed evidence behind. With mountains of DNA, fingerprints, and clothing left at the scene, this case should have been easily solved.