C509 Tracing

"What is the method?"

"Honestly, we don't know." The policeman shook his head.

Zhang Meng twitched his mouth and said, "Serial killers and serial kidnappers, I think cops like you can only do this much."

The police officer's disdainful tone made it hard for the monk to understand what was going on. Aren't you a police officer yourself? Why did he speak in such a tone?

In the end