The murderer of Tang Tan II was Song Yi. He used the criminal doctor to frame his own crime. On the surface, the murderer was an American doctor, but the murderer behind it was Song Yi. This was the specialty of the Detective Series in Chinatown. The real murderer had not been brought to justice because there was no direct evidence. It was just Qin Feng's speculation. In the second part, Qin Feng discovered Song Yi's criminal behavior, but ultimately chose to let him go. The specific reason might be that there was insufficient evidence to directly bring him to justice, and Qin Feng might have other considerations. In short, according to the information provided, Song Yi was the murderer of Tang Tan's second film.
The murderer in Detective Chinatown 2 was Dr. James. He had murdered many people because of his obsession with the Chinese cultivation method. His wife was Chinese. When she passed away due to illness, James was disappointed with Western medicine and decided to treat himself through alchemy. However, despair turned him into a murderous demon. Although there were some clues and identities, it was easy to infer that he was the murderer from the victim's wounds and modus operandi. The police gradually discovered his true identity during the investigation.
There were a few possible murderers. According to the plot of Detective Chinatown 2, the murderer could be the experimental genius surgeon James Springfield. He used the Taoist theory of Yin and Yang to kill people in New York City. The other possible murderer was Detective " Q " Song Yi. He used this case to manipulate the other detectives behind the scenes and took the opportunity to kill Lu Guofu and frame James Springfield. There was also a theory that the little girl, Snow, was the murderer who directed everything. She used her adoptive father to kill. However, there was no clear answer as to who the real murderer was. Therefore, there was no conclusive answer as to who the murderer of Detective Chinatown 2 was.
The murderer in the movie Detective Chinatown 1 was Snow. By writing in her diary, Sino made her adoptive father think that she was being bullied by Sompa. Then, she wrote down the method to kill Sompa in her diary, enticing her adoptive father to kill Sompa. It was very likely that Sino and Dan were in a mutually beneficial relationship.
There were some clues that could lead to a conclusion about the murderer of Detective Chinatown 2. According to the description in the second document, the police had identified Tang Ren as the murderer of Sompa through surveillance videos and fingerprints. In addition, the fourth document mentioned that the doctor was the murderer of the whole case, but Song Yi also killed Wang Xun's character. Although these clues did not provide a conclusive answer, it could be inferred that Tang Ren and Song Yi might be the murderers in Detective Chinatown 2. However, because the search results provided did not have a clear answer, it was impossible to determine the true identity of the murderer. Therefore, I don't know the exact answer to the murderer of Detective Chinatown 2.
The murderer of the second case of Duke Di of Tang was Teng Kan.
The murderer in the movie Detective Chinatown 2 was Dr. James. His motive was because his wife was Chinese. After he was disappointed with Western medicine, he tried to cure himself through alchemy rituals, but in the end, he became a murderous demon. In addition, there were some misleading and hidden information about the identity of the murderer, but in the end, Qin Feng found the details of the murderer.
Tang Tan 2's real culprits were the doctor and Song Yi. The doctor carried out five consecutive killings and used the forensic doctor's crime to cover up his actions. Song Yi killed Lu Guofu and swapped his body with the fourth victim. These two people acted separately, but their actions were eventually discovered by Qin Feng and Tang Ren. Therefore, the doctor and Song Yi were the real culprits of Tang Tan 2.
Bai Xiaochun was the murderer of "The Hundred-Faced Detective" and "Dreaming in the Garden."
Song Yi in Detective Chinatown 2 was suspected to be the murderer, but there was no clear evidence to prove that he was the real murderer. Qin Feng deduced that Song Yi was the murderer of Lu Guofu, but the others had different opinions on Song Yi. Some articles mentioned that the people in the community still believed that Song Yi was the murderer, and other detectives did not deny Song Yi's suspicion. However, there were also articles that mentioned that Song Yi might just be using this case to avenge his sister, and the real murderer might be the doctor. In summary, based on the information provided, it was impossible to determine if Song Yi was the murderer.