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

Chapter 1477 On-site identification and reconstruction of the process

To further solidify the evidence and confirm that the details of the crime perfectly matched the on-site investigation and autopsy results, on the morning of the day after Sun Qingguo's arrest, Xiao Yang and Xiao Sun, along with investigators and forensic doctor Zhang Lin, escorted Sun Qingguo to the crime scene in the urban village for identification. The alleyway had been unblocked by then, but faint investigation markings remained on the ground, the wooden door of the abandoned coal shed was still tightly closed, and the air still carried the mixed smell of dirt and rust, mirroring the atmosphere of the night of the incident.

As soon as he stepped into the alley, Sun Qingguo's body trembled uncontrollably. His steps faltered, and his eyes darted away, avoiding eye contact with the corner of the wall. "It's here," he finally stopped at the spot where the deceased Li Baoquan had fallen, his voice hoarse, at Xiao Yang's prompting. "I strangled him right here." He pointed to a dent in the corner of the wall. "Li Baoquan was standing here with his back to me, facing the coal shed door, cursing me. He said I had ruined his family and that I would pay the price. When he wasn't looking, I took out a thin wire that I had hidden in my pocket beforehand."

Sun Qingguo raised his hand to demonstrate the actions at the time, his fingers stiffly simulating the entanglement: "I specifically chose a low-carbon steel wire with a diameter of 0.3 centimeters for this wire, because it's thin yet strong, allowing for concentrated force when strangling the neck, and making it difficult for the person to break free. I wrapped it around his neck once, grabbed both ends of the wire with both hands, and pulled it to both sides with all my might." He paused, then added, "I'm about the same height as him, both over 1.7 meters. I stood directly behind him, keeping my arms horizontal, so the ligature groove is straight, without any tilt. This is what you forensic doctors call a 'horizontal circular ligature groove.'" This description perfectly matches the description found during Zhang Lin's autopsy: "The ligature groove is horizontal, with neat edges, and a width of 0.32 centimeters."

Zhang Lin squatted down and pointed to the fine scratches on the ground, asking, "Where did these scratches come from?" Sun Qingguo looked down, his eyes flickering. "I made them accidentally while I was committing the crime. When I strangled him, his body instinctively struggled forward, and the other end of the wire in my hand accidentally scraped against the ground. Also, the handle of the stainless steel cutting knife in my pocket made a few scratches on the ground." Zhang Lin then used tweezers to remove the dirt around the scratches and added, "The industrial paint residue on the scratches is exactly the coating on your cutting knife, and it matches the residue we extracted perfectly."

"How long did he struggle?" Xiao Sun asked. Sun Qingguo shook his head: "Not much. I applied force steadily, and the wire instantly tightened around his carotid artery. He only let out a muffled groan, kicked his hands and feet a couple of times, and then lost his strength." This corroborated the autopsy findings that "the subcutaneous bruising around the rope groove was relatively light, there were no obvious overlapping scratches caused by struggle, and no foreign objects remained under the deceased's fingernails," explaining why Li Baoquan did not leave any effective resistance wounds. Sun Qingguo continued, "I maintained the applied force for a few minutes until he was completely still, his eyes wide open, his mouth agape, exactly as you found him."

He then led the group to a wall about a meter from the crime scene, pointing to several faint scratches: "These scratches were also made by me. After strangling him, I moved his body to the corner and curled up, trying to make it look like an accidental fall. When I got up, my elbow accidentally hit the wall, and the cutting knife in my pocket rubbed against the brick wall, leaving these marks." Xiao Yang took out photos of the crime scene for comparison, and the location and length of the scratches were completely consistent with the photos, further confirming the authenticity of his confession.

Regarding the details of framing Zhang Qiang, Sun Qingguo confessed, "I had planned to frame Zhang Qiang long ago. I had dealt with him before when I ran a repair shop. I knew he worked in a machine factory and often used these thin wires and cutting tools. Also, he was about my size and wore size 42 shoes." He pointed to the footprints on the ground, "I deliberately wore the same diamond-patterned sneakers as him, and I walked slowly to imitate his usual stride, just so you would suspect him after extracting the footprints." The technicians compared Sun Qingguo's gait with the footprints on site. The stride length and forefoot pressure distribution matched the plaster model, ruling out Zhang Qiang as the suspect.

"How were the murder weapon and the evidence used to frame him handled?" Xiao Yang pressed. Sun Qingguo replied, "I deliberately left the wire that strangled him on the ground near his hand, so you would find it and mistakenly believe it was left by Zhang Qiang during the crime. I accidentally chipped a small piece of stainless steel off the cutting tool, which fell to the corner of the coal shed. I didn't dare pick it up, thinking that this piece could also point to the mechanical repair personnel. Afterwards, I took out a tissue from my pocket, wiped the fingerprints off the wire and the cutting tool, then put the tissue away and threw it into the trash can outside the alley." This was completely consistent with the scene investigation, which found "no clear fingerprints on the surface of the wire and a stainless steel fragment extracted from the corner of the coal shed." Zhang Lin added, "The texture and material of the fragment are exactly the same as those on the cutting tool in your house, and the wear on the tool's blade matches the force of the scratch."

Finally, Sun Qingguo pointed to the east exit of the alley: "After I finished dealing with the scene, I walked out along this road, deliberately keeping my head down to avoid the poorly positioned surveillance camera at the alley entrance, leaving only a blurry silhouette. After reaching the exit, I got into the black sedan that had been parked in a blind spot of the surveillance camera and drove home. Once home, I immediately washed my mud-stained coat and shoes, but they weren't completely clean, leaving behind traces of mud from the crime scene and a small amount of blood from the wire. These became the evidence you used to arrest me." His confession fully reconstructed his escape route after committing the crime, forming a closed loop with the surveillance footage, vehicle movements, and evidence testing results.

Zhang Lin meticulously documented the entire identification process, meticulously comparing Sun Qingguo's confession with the autopsy report: "The shape of the grotto, the method of exertion, and the duration of the death all perfectly match the autopsy's conclusion of 'mechanical asphyxiation, time of death between 11 PM and midnight, and a rapid death without violent struggle'; the remaining tool fragments and paint residue also correspond to the results of trace evidence testing." With this, the on-site identification was complete, and all details of the crime corroborated the on-site investigation and autopsy findings, creating a completely closed chain of evidence.

The alleyway in the urban village has long since returned to its former tranquility. The chalk marks on the walls, left by the investigation, have been washed away by the rain, as if that harrowing murder had never happened. But for every investigator involved in the case, it was a profound experience, further strengthening their resolve to uphold justice and combat crime. No matter how complex the case, no matter how cunning the killer, as long as we persist in seeking the truth and persevere, justice will ultimately prevail.

In the Criminal Investigation Division's office, new case files were delivered to Li Ming's desk, and a new round of investigation was about to begin.