Attending ex-girlfriend's wedding, arresting the groom's officer on the spot

"Check Li Mengmeng's guardian," Wang Shuai said into the walkie-talkie. "Also, check the business registration information for Hongda Cleaning Company to see if it's still operating." The technician quickly replied, "The company was deregistered five years ago. The legal representative was Sun Zhiguo, who now runs a building materials store in the logistics park on the outskirts of the city."

As night fell, Xiao Zhang found a plastic bag tucked into a crevice in the bed frame. Inside, a stack of photos fell out: Li Baoquan, dressed in sanitation worker's uniform, stood smiling beside a garbage truck; a little girl with pigtails held up a certificate of merit against a backdrop of dilapidated brick houses; and in another group photo, he and a strange man had their arms around each other, with a tin shed behind them bearing the words "Hongda Sanitation."

"Who is this man?" Wang Shuai asked the station manager, pointing at the photo. The manager squinted and stared at it for a while: "He looks like Old Wang, who used to sweep the streets with him. I heard he went to drive a truck later." Just then, Zhang Kai's text message came in: Sleeping pills were detected in the deceased's stomach contents. The dose was not enough to be fatal, but enough to make him unconscious.

Wang Shuai suddenly stared at the tin shed in the photo. There was a dent in the billboard on the roof, the shape of which closely matched the blunt force trauma to the victim's skull. "Go check the old address of Hongda Cleaning," he said, grabbing his coat and heading outside. "We have the killer's DNA. Now we need to find his connection to Li Baoquan—the man in this photo, and that Sun Zhiguo, we need to investigate them both."

Lu Chuan pinned Sun Zhiguo's photo to the center of the whiteboard, surrounding it densely covered with evidence: yellowed documents from the cancellation of Hongda Cleaning Company, handwriting on Li Baoquan's remittance slip, clues faintly visible in the truck repair records, and the dent in the tin shed in the crucial photo. "Focus on investigating all vehicles registered under Sun Zhiguo's name, especially their driving routes during the time of the incident." He heavily traced the words "Former Site of Hongda Cleaning" in red pen, leaving a striking mark on the whiteboard.

Investigators reviewed traffic surveillance footage and discovered that on the night of the incident, a silver Wuling Rongguang pickup truck registered under Sun Zhiguo's name passed the intersection closest to the body dumping site at 2:17 AM. The vehicle's GPS records showed that it had stopped near an abandoned factory for as long as forty minutes. Even more alarming, the vehicle underwent a complete repaint three days after the incident, and the repair record for "replacing the rear cargo floor" was deliberately obscured with correction fluid.

"Action!" Lu Chuan gave the order, and the SWAT team quickly surrounded Sun Zhiguo's building materials store. It was midday, and Sun Zhiguo was dozing on a recliner by the store entrance, a noisy storytelling playing on a radio beside him. The moment the cold handcuffs gripped his wrists, the slightly overweight middle-aged man jolted awake, a flash of panic crossing his face, but he quickly regained his composure: "Officer, what are you doing? I'm a law-abiding citizen!"

In the interrogation room, the incandescent light was blinding. Sun Zhiguo, with his legs crossed, rubbed the jade thumb ring on his finger, a faint, cold smile playing on his lips: "Li Baoquan and me? We haven't been in contact for a long time. What does his death have to do with me?" Faced with vehicle surveillance footage and maintenance records, he vehemently denied it: "The car belongs to the company. There are so many drivers, how would I know who drove it where?"

Wang Shuai slammed the yellowed group photo on the table: "How do you explain this photo? You and Li Baoquan were old acquaintances when you were working at Hongda Building Materials Store. He was frequently seen visiting your store a week before he disappeared." Sun Zhiguo glanced at the photo and suddenly burst into laughter: "Based on this? There were plenty of people working with us back then. Are you going to blame me for everything that happened to them?"

Zhang Kai rushed over with the latest autopsy report: "Iron oxide was detected in the depression of the deceased's skull, which is completely consistent with the coating composition of the steel pipes sold by Sun Zhiguo's building materials store." Lu Chuan pushed the test report in front of Sun Zhiguo, but he remained unmoved: "Building materials stores have so many goods coming in and going every day, who knows where these steel pipes have gone?"

The interrogation reached a stalemate, with time ticking away. Sun Zhiguo began to close his eyes and rest, responding with "I don't know" and "I don't remember" to whatever evidence the investigators presented. Lu Chuan, watching the calm expression on the monitor screen, realized this was a difficult psychological battle.

"Check his communication records, focusing on all unfamiliar numbers before and after the incident." Lu Chuan redeployed his team. "Also, interview the employees at his building materials store and look for breakthroughs in their daily lives." Soon, an important clue surfaced: Sun Zhiguo's accountant revealed that the boss had recently been going fishing at a fishpond in the suburbs, always carrying a black tin box.

Investigators found the water-stained tin box in the reeds by the fishpond. Inside, they found 300,000 yuan in cash neatly stacked, each bundle tied with red string, along with a yellowed ledger. The ledger was filled with numerous "special expenditures," one of which read: "October 15, 2023, Li Baoquan, hush money, 100,000 yuan."

When the ledger was slammed in front of Sun Zhiguo, his expression finally changed, but he still remained defiant: "Doing business inevitably involves some shady dealings. Giving money to shut people up is normal. Is that illegal?" Lu Chuan suddenly changed the subject: "The surveillance cameras by your fishpond captured some interesting footage. On the night of the incident, the taillights of your pickup truck passed by the fishpond at three in the morning. What were you doing at that time?"

Sun Zhiguo's pupils contracted sharply, and his Adam's apple bobbed. He remained silent for a long time, then suddenly slammed his fist on the table in a fit of rage: "I want to see a lawyer! Arresting people without evidence? I'm going to sue you!" The atmosphere in the interrogation room was tense, and the investigators knew that this battle with the cunning murderer had only just entered its most crucial stage. Outside the window, dark clouds gathered, and a downpour was imminent, just like the truth of the case, shrouded in layers of mystery, waiting to be fully revealed.

When Zhang Kai stormed into the interrogation room with the latest DNA test report, Lu Chuan was staring at Sun Zhiguo's bloodshot but still stubborn eyes. The words "99.99% match" on the test report gleamed coldly under the incandescent light. Wang Shuai slammed the report heavily on the metal table, the sound of the paper hitting the surface echoing in the small space: "Sun Zhiguo, the skin tissue under Li Baoquan's fingernails is yours!"

Sun Zhiguo's well-maintained fingers suddenly began to tremble uncontrollably, the jade thumb ring tapping softly on the table. He forced a cold laugh: "Maybe it's from when we were working together before. I was his colleague." Before he could finish speaking, Lu Chuan pulled up the surveillance footage—in the video, Sun Zhiguo's truck was seen sneaking into the abandoned factory during the time of the incident, its headlights sweeping across the rusty iron gate like a pair of spying eyes.

"The 100,000 yuan hush money payment from October 15th is clearly recorded in the ledger." Wang Shuai opened the yellowed ledger in the evidence bag. (End of Chapter)