If Jian Yiling wanted to kill Qin Hongzhi, why would she need to use such a stupid approach?
First of all, she could just refuse to save Qin Hongzhi. Without her help, Qin Hongzih would soon die. And thus, why would she need to go to such trouble?
Secondly, Jian Yiling herself was a forensic pathologist. She knew about toxicology testing and what types of toxins could be tested. Therefore, she had the ability to use poisons outside of the testing. Why would she be stupid enough to let people figure out what poisons she was using?
Finally, who would put such a poison in the medicine that they were delivering? That was essentially making a public announcement and telling everyone that Qin Hongzhi died because of something I sent. Was Jian Yiling that stupid?
Superintendent Ruan: "In order to not attract attention, I asked Captain Fei to assist in the investigation. Therefore, he invited you to leave the Zhai Residence."