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

"It seems the killer disposed of the other murder tools and the victim's belongings, or discarded them elsewhere, after throwing away the backpack," Xiao Sun said. Xiao Yang nodded: "That's a possibility. We need to expand our search area and not overlook any corner."

At noon, the investigation had been going on for over six hours. The team members hadn't rested or eaten lunch, and everyone was exhausted. However, in order to find clues as quickly as possible, no one complained. Li Ming arranged for his team to bring everyone boxed lunches and water, allowing them to take turns resting and eating. Xiao Yang and Xiao Sun ate a few bites and then returned to their investigation.

At 1 p.m., Xiao Yang and Xiao Sun discovered something unusual at a sewer opening on the south side of Heping Road. The sewer cover showed signs of having been moved, and there were small amounts of blood and dirt on the surrounding ground. "Xiao Sun, there's something wrong with this sewer opening," Xiao Yang said. The two of them worked together to move the sewer cover off, and a foul stench wafted out of the sewer.

Xiao Yang took out a powerful flashlight and shone it inside the sewer. There was a small amount of water and trash in the sewer, and at the edge of the water, he found a bloodstained kitchen knife! "Found it! There's a bloodstained kitchen knife here!" Xiao Yang shouted excitedly. Xiao Sun immediately took out his camera and photographed the knife and the surrounding environment of the sewer opening. Then, Xiao Yang carefully used tweezers to pull the knife out of the sewer.

The kitchen knife is made of stainless steel, about 30 centimeters long, with a blade about 20 centimeters long and a black plastic handle. There are obvious bloodstains and human tissue residue on the blade, and several chips along the edge, indicating it's an old knife that has been used many times. "This kitchen knife is very likely the murderer's weapon!" Xiao Sun said excitedly. "The bloodstains and human tissue on the blade were probably left when cutting up the body."

Xiao Yang collected bloodstains, human tissue, and fingerprint samples from the kitchen knife, and then investigated the environment around the sewer opening. "There were trampling marks and drag marks on the soil around the sewer opening, indicating that the murderer may have discarded the kitchen knife into the sewer here," Xiao Yang said. "We collected these trace samples for analysis and comparison."

Just as the two were inspecting the sewer opening, the team member responsible for retrieving the surveillance footage sent a message: "Xiao Yang, Xiao Sun, we retrieved the surveillance footage along Heping Road and found that between 11 p.m. last night and 2 a.m. this morning, a white van was driving slowly along Heping Road and stopped near several trash cans, behaving very suspiciously. However, due to the old surveillance equipment and the poor lighting at night, we cannot see the van's license plate number or the driver's face clearly."

“Okay! We understand!” Xiao Yang replied. “Continue to retrieve surveillance footage from the surrounding roads, focusing on the driving trajectory of this white van, and see if we can find a clear license plate number and driver information.” After hanging up the phone, Xiao Yang said to Xiao Sun, “It seems that this white van is very likely the vehicle used by the murderer when disposing of the body parts. We must find this van and the driver as soon as possible.”

At 2 PM, Xiao Yang and Xiao Sun completed the first round of on-site investigation of Heping Road and the surrounding 1-kilometer area. After a full day of intensive investigation, they collected a total of 23 blood samples, 15 human tissue samples, 8 fingerprint samples, 12 footprint samples, 10 fiber samples, as well as important physical evidence such as fragments of a black backpack and a bloodstained kitchen knife. Meanwhile, the investigators also interviewed nearby shops, residents, and sanitation workers, collecting a wealth of information.

Xiao Yang and Xiao Sun organized all the clues and physical evidence they had collected and gave a detailed report to Li Ming. "Team Leader Li, after a comprehensive investigation, we have determined that this is a dismemberment murder case. The victim is an adult male, preliminarily estimated to be between 35 and 45 years old, approximately 178 cm tall, and weighing approximately 70 kg. After dismembering the victim, the murderer took a white van and scattered the remains in various trash cans along Heping Road. The crime occurred roughly between 11 PM last night and 2 AM this morning," Xiao Yang reported.

"We recovered a bloodstained kitchen knife from the scene, which we preliminarily determined to be the murder weapon; we also recovered fragments of a black backpack, suspected to be one of the victim's personal belongings; and we collected a large number of bloodstains, human tissue, fingerprints, footprints, and other samples, which will require further identification and analysis by the technical department. In addition, we found that the locations where the murderer disposed of the body remains were arranged in a linear pattern along Heping Road, suggesting that the murderer disposed of the remains along Heping Road while driving," Xiao Sun added.

Li Ming nodded and said, “Very good! Your investigation work is very thorough. Next, each group will carry out its work according to the following division of labor: Group 1, continue to retrieve surveillance footage from Heping Road and surrounding roads, focusing on the white van, and be sure to find the license plate number and driver information; Group 2, conduct technical identification on all the physical evidence collected, including DNA identification, fingerprint comparison, footprint analysis, etc., to confirm the murder weapon and the victim's identity information; Group 3, conduct further interviews with surrounding shops, residents, and sanitation workers to understand information on suspicious persons and vehicles during the time of the incident; Group 4, wait for the autopsy results from the forensic identification center, and further narrow down the scope of the investigation based on the autopsy results.”

"Understood!" all team members responded in unison. Immediately afterwards, each group began work according to Li Ming's instructions. Xiao Yang and Xiao Sun, meanwhile, returned to the technical section of the municipal criminal investigation detachment with the collected evidence to assist the technicians in their identification and analysis.

Back in the technical department, Xiao Yang and Xiao Sun sent the extracted bloodstains and human tissue samples to the DNA lab, the fingerprint samples to the fingerprint identification lab, the footprint samples to the footprint analysis lab, and the fiber samples to the trace evidence lab. The technicians immediately threw themselves into the intense identification work, everyone racing against time to get the results as quickly as possible.

"Xiao Sun, what do you think the killer in this case is?" Xiao Yang asked while organizing the investigation records. Xiao Sun thought for a moment and said, "Judging from the killer's modus operandi, the dismemberment was rather crude, indicating that he probably doesn't have professional autopsy knowledge and is most likely an ordinary person. Moreover, the killer has a certain level of counter-investigation awareness, knowing how to disperse and dispose of the body parts, choose blind spots in surveillance cameras, and discard the murder tools, which suggests that he may have a criminal record or pays attention to criminal investigation information."