Review of the Mudanjiang serial robbery and murder case: The murderer walked alone at night and killed 6 people in a row. What was the result?

From 1991 to 1994, a series of murders and robberies occurred continuously in Chaihe, Mudanjiang, and Hailin cities. All six cases were committed by a gang of two people.

On April 22, 1991, the Criminal Investigation Division of Chaihe Forestry District, Hailin City discovered that Zhao Weishi (male, 29 years old), an internal clerk, had not been at work all day, so they sent someone to search and found him and his daughter Zhao Yu. Killed at home. After the incident, the Provincial Public Security Department, the Provincial Forestry Public Security Bureau and the Mudanjiang Forestry District Public Security Bureau all sent personnel to the scene. During the investigation, they recovered 2 murder weapons (ashtrays and 2 ropes) and 1 incomplete sock footprint on the floor tiles of Zhao's house. Mei et al.

At the same time, it was discovered that a "June 4th-style" pistol and a magazine worn by Zhao had been stolen. After investigation, it was learned that Zhao Weishi and his wife were not getting along, and both of them had an improper relationship. The task force suspected that the criminals were motivated to kill because of adultery, and that the reason for grabbing the gun was to divert the attention of the police. After a lot of work, the major suspect Wang Weiguang was interrogated. Wang explained the crime process, but did not explain the whereabouts of the gun. Later, he overturned the testimony and the case failed to enter the litigation process.

On January 17, 1994, the Hailin City Criminal Police Brigade received a report and rushed to the home of Wang Jiancai, head of the Vehicle Management Section of the Traffic Police Team of the Municipal Public Security Bureau, and saw Wang and his three children separated. Killed in 3 rooms. Wang Jiancai was shot 4 times, and each of the three children was shot once. A bloody fingerprint was extracted from the bathroom door handle. 5 "May 4th-style" pistol bullets and 7 shell casings were extracted from 3 rooms. Footprints were extracted from the sofa and the floor. Wang Jiancai's daughter Wang Wei is a survivor. According to her description, at about 4:10 that afternoon, she was cooking in the kitchen and her father returned home. Soon after, two strangers came in, one tall, one short, one fat and one thin, both about 40 years old.

Deputy Director Zhang admitted that he and Wang Chengyan were good friends; they had done a business of reselling tiger penises together, and avoided talking about anything else. He is a public security cadre with many years of work experience. When he was a policeman at the police station, he received third-class merit for his outstanding work. He also served as a pre-interrogator and was very familiar with interrogation strategies. Although the public security authorities obtained many clues and information at that time, they had not yet obtained direct evidence. If Zhang insisted that the items found in the search were given to him by Wang Chengyan, the interrogation would reach a deadlock.