A highly intelligent crime

"The mastermind?" Ren Xiaosu looked at the Northwest's intelligence agent who came to report the matter. "How can we be sure that it's the mastermind?"

The Northwest's intelligence agent explained, "Wang Yun said the person appeared at the intersection where Mr. Jiang Xu was killed. Two hours later, he reappeared at the spot where Mr. Jiang Xu was nearly crushed by a falling billboard as though nothing had happened. This is a classic case of the guilty returning to the crime scene to secretly check on things. Furthermore, he was extremely cautious about it. Most field personnel would definitely not do such a thing, and only the person planning behind the scenes would go back to the scene of the crime."