The police did not know much about Yan Songnan's past. After all, you Yi was almost done with it. Besides, nie qiuping had changed her name and returned to the Xia family's household register. Information was not as developed in this era.
Therefore, there were some things that couldn't be investigated if someone deliberately wanted to hide it.
However, the police had a rough understanding of you Yi's current wife. She was probably Yan Zhennan's ex-wife.
However, that was the key. You Yi was so powerful and had a high status. If you wanted to see his wife, he would let you see her. If you went to see her, you would not end up well. You might even be taught a lesson.
Furthermore, the police had investigated Yan Zhennan's character and found that he was a complete B * stard.
It was perfectly normal for his ex-wife to leave him. No woman would be willing to live with a man like him.
Hence, the police would never look for Yan Zhennan's ex-wife for him.