The crackdown on organized crime began with the arrest of the mother-in-law.

By reviewing Chen Ershan's call records, it was found that he made three calls between 8 pm and 9 pm three days ago. The callers were all owners of scrap metal recycling stations, and the content of the calls was to inquire about scrap metal purchase prices. There was no abnormal information.

The team also visited Chen Ershan's rented accommodation. Chen Ershan rented a dilapidated house in the northern suburbs; the room was cluttered and piled with various scraps and worn-out clothing. Inside, the team found several black long-sleeved T-shirts and dark jeans similar in style to the deceased's clothing, but no clothing matching the white synthetic fibers found at the scene. Furthermore, a lock-picking tool was found in the room, similar in characteristics to the tool used to pry open Li Qingfeng's tricycle lock, further confirming that Chen Ershan was the vehicle thief.

“Chen Ershan stole Li Qingfeng’s tricycle to collect scrap. Three days ago, he rode the tricycle to the scrap yard to sell scrap three mornings ago. That night, he was murdered and his body was dumped at the landfill,” Xiao Zhou explained. “Based on the on-site investigation and the forensic autopsy results, Chen Ershan was probably murdered and then transported to the landfill by the suspect using the stolen tricycle. On the way, the tricycle had a flat tire, so the suspect went to ‘Old Yang’s Auto Repair Shop’ to get it fixed. After the tire was fixed, the suspect abandoned the body and the tricycle at the landfill.”

However, despite confirming the victim's identity, the investigation stalled once again. The suspect had covered his face while repairing the tire, making his appearance unrecognizable on surveillance footage; Chen Ershan had a complex social network with multiple prior theft convictions, making it difficult to identify the target of the revenge killing; fingerprints collected at the scene, after being enhanced, failed to match in the fingerprint database; DNA samples from cigarette butts were confirmed to be from the suspect, but again, no match was found in the DNA database; white synthetic fiber samples, after comparison, excluded clothing fibers from Chen Ershan and Li Qingfeng, confirming they were left by the suspect, but currently, the suspect's identity could not be determined through the fibers.

Xiao Zhou's team also conducted a comprehensive investigation into Chen Ershan's activities before the incident. Surveillance footage showed that three days prior, in the morning, Chen Ershan rode his tricycle from his rented apartment to a scrap metal yard to sell recyclables; at noon, he ate at a small restaurant, and afterwards went alone to a card and mahjong parlor in the northern suburbs; at 3 PM, he left the parlor and rode his tricycle towards "Old Yang's Auto Repair Shop," after which he was never seen on camera again. Based on the forensic examination's estimate of the time of death as around 9 PM, it is highly likely that Chen Ershan was controlled and murdered by the suspect between 3 PM and 9 PM.

The team members interviewed staff and customers at the card room and the small restaurant. The card room owner stated that Chen Ershan played cards for a while that day, lost money, and left without arguing with anyone. The restaurant owner stated that Chen Ershan ate alone that day and did not behave unusually. No one could provide information on Chen Ershan's whereabouts after leaving the card room, nor did anyone see any suspicious persons with him.

To date, although the case has made significant progress, identifying the deceased as Chen Ershan, the tricycle thief, and reconstructing the suspect's body disposal route, crucial clues pointing to the perpetrator remain missing. The suspect possesses strong counter-investigation awareness, deliberately concealing his face after the crime and leaving no clear identifying information; Chen Ershan's social relationships are chaotic, raising the possibility of a revenge killing, a robbery, or a crime of passion, making the scope of the investigation extremely broad.

After Xiao Zhou reported the investigation results to Li Ming, Li Ming convened another case analysis meeting. "Although we have confirmed the identity of the deceased, the investigation still has a long way to go," Li Ming said. "Next, we will work in three groups: First, we will continue to expand the scope of surveillance and investigation, focusing on Chen Ershan's activities from leaving the card room until the time of the incident, and looking for suspicious persons who accompanied or contacted him; second, we will conduct an in-depth investigation into Chen Ershan's social relationships, especially those with whom he had conflicts, and eliminate suspects one by one; third, the technical department will speed up the comparison of fingerprint and DNA samples extracted from the scene, and at the same time conduct further analysis of the white synthetic fiber samples to try to determine the source of the fibers."

After the meeting, the investigation teams plunged back into their intense work. The joy of identifying the victim was quickly overshadowed by new challenges. The members of the criminal investigation team knew that to identify the suspect, they would have to put in even more effort and search for clues in more details. The investigation into the murder case at the northern suburban landfill remained fraught with unknowns and challenges, but the investigators did not back down. They firmly believed that justice might be delayed, but it would never be absent.

As per Li Ming's plan, the second investigation team, led by Xiao Wang, was specifically tasked with thoroughly investigating Chen Ershan's social connections, focusing on those with whom he had conflicts or disputes. The morning after the deceased was confirmed to be Chen Ershan, Xiao Wang led his team to conduct a comprehensive investigation, starting with Chen Ershan's household registration information.

“Chen Ershan’s registered residence is in Chenjia Village, Qinghe County, a neighboring city. His parents died early, and he has no spouse or children, nor any direct relatives in the local area,” said team member Xiao Liu, sorting through the household registration information. “We contacted the Qinghe County police and verified that Chen Ershan had been idle in the village since he was a child. He ran away from home at the age of 16 and has been wandering around for many years. He rarely returns to the village, and most of his relatives in the village have cut off contact with him.”

"Since there are no immediate family members, we'll start with his collateral relatives and friends," Xiao Wang said. "We'll contact the Chenjia Village Committee, find his uncles, cousins, and other collateral relatives, and ask them if they have any contact with Chen Ershan, to understand his personality and the people he associates with outside." Afterward, Xiao Wang led his team to Chenjia Village in Qinghe County, a neighboring city.

Chenjia Village is a remote village with inconvenient transportation. When they arrived in the village, it was already noon. After learning the purpose of their visit, the village head, Chen Deming, shook his head repeatedly: "Chen Ershan has been a bad boy since he was a child. He steals chickens and dogs. After his parents passed away, no one could control him. The relatives in the village all think he is a disgrace and few people associate with him. He hasn't been back to the village for five or six years."

Led by the village head, Xiao Wang's team found Chen Ershan's second uncle, Chen Jianjun. Chen Jianjun mentioned, "Ershan was a withdrawn and irritable boy who often got into fights when he was young. After leaving home, he would occasionally call me, always asking for money. I advised him several times to find a proper job, but he never listened. About half a year ago, he called me, saying he had fought with someone in the city over territory and got beaten up. He said he wanted to get revenge, but he didn't say who it was." This information made Xiao Wang realize that Chen Ershan's mention of "fighting for territory" was likely related to his death.