1. Zhu Lingthallium poisoning incident refers to an incident in which Zhu Ling, a Tsinghua University student, developed bizarre thallium poisoning symptoms during his school days, which caused great harm to his health and was finally diagnosed and treated with the help of the Internet.

2. Because Zhu Ling has no history of exposure to thallium, the police decided that it was a poisoning incident. However, after investigation, the case has experienced many twists and turns, and the murderer is still at large, with no clear result. However, due to some unusual behaviors of the police in handling the incident, Zhu Lingan became a public event, which triggered various speculations about the suspect's family background.

3. Sun, his roommate, was taken away as a suspect by the police on 1997. The police said she was "the only student who had access to thallium". Later, Sun was released. Over the years, many netizens thought that Sun had a motive for committing crimes, and knew the nature of thallium and had access to thallium, so they suspected that he had poisoned it and kept calling on the police to restart the investigation. 20 13, 16 04 06 With the report of Fudan poisoning case, the call for a thorough investigation of Zhu Lingan reappeared, and the former suspect Sun Wei was widely disputed by public opinion. On May 8, the Beijing Public Security Bureau responded through the official Weibo that it could not be detected because of the loss of evidence, and there was no interference in the process, calling on the public to treat the case rationally.