Was it Atomura-san or Nekota-san who did the crime? In the solution part, it was revealed that the latter did the burglary and the murder. He pushed off the former when the truck was still at the old office and made the burglary afterwards. With his triathlon skills, he jumped off from the old office to the new one. He used a rope that is teice the length of the old office veranda on th 9th floor and the veranda of the new one. Then using twice the length of the rope he passed the rope through the veranda fence on the old office, made a loop then tied the ends together. After that, he made a smaller loop just large enough to fit his body and tied it to the rope on the veranda, and threw that small loop across the rooftop to the next building. By pretending to be caught on the roof, he covered the rope with his long coat. He tied the small loop to his body and jumped down and used his bed matress as a cushion.

In the end, it seems like Takagi-keiji was fooled by Yumi-san. When Miwako-san saw the brooch she said that it was what Yumi wanted. It seemed that the whole world crashed to Takagi-keiji.