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

“That’s the real reason he left,” Zhang Hui said, closing the file with dusty fingertips. “Zhao Zhiqiang discovered that the actual size of this batch of steel bars was one size smaller than what was written in the ledger, and he refused to sign off on the warehousing. He argued with General Manager Zhou several times. General Manager Zhou felt that he was making a mountain out of a molehill and that it was affecting the company’s procurement schedule. The conflict between the two deepened, and in the end, Zhao Zhiqiang left.” Old Li, a long-time employee in the warehouse, also confirmed this: “They argued fiercely that day. General Manager Zhou said, ‘If you don’t want to work here, then get out.’ Zhao Zhiqiang didn’t mince words and said, ‘Fine, I’ll leave. I don’t want to stay in a company like this.’ Then he packed his things and left, and never came back.”

When Zhao Zhiqiang's DNA test results came back, Zhang Hui was organizing files in his office. Sunlight streamed through the blinds, casting dappled patterns on the desk. "STR typing: 16 loci, only 3 matches, paternity index 0.02," the red "Excluded" on the report was particularly striking, like a needle piercing all previous speculations. "His connection to the deceased can be completely ruled out." He categorized Zhao Zhiqiang's file into the "Unrelated Personnel" folder, the folder's thickness just enough to obscure the words "Hongwei Building Materials"—this seemingly crucial clue ultimately proved to be a coincidence, devoid of any real value.

Zhang Hui rubbed his aching shoulders, picked up the water glass on the table, and took a sip. The water was cold, and it slid down his throat with a slightly bitter taste. He opened his investigation notebook, which was filled with detailed notes from the past two days' investigations, from Hongwei Building Materials to Zhao Zhiqiang's hometown, and then to the coastal city—every location and every time point was recorded clearly. He drew a thick line next to Zhao Zhiqiang's name, with notes such as "height mismatch, no femoral fracture, alibi, DNA excluded"—each point acting as solid evidence, completely removing Zhao Zhiqiang from the suspect list.

New questions flooded the mind: Where did the rice in the deceased's stomach come from? Was it homegrown, or bought from a small grain store? Was the scar on his right ring finger a professional feature or a coincidence? Was it from an injury sustained at work, or was there another reason? But what was certain was that Zhao Zhiqiang's relationship with Hongwei Building Materials had nothing to do with this case; this lead, which had been investigated for two days, ultimately proved to be a false alarm.

The setting sun streamed through the window, casting a golden halo over the words "exclude." Zhang Hui watched the sun gradually sink below the horizon, his heart filled with mixed emotions. The past two days of running around, while failing to find any leads related to the case, had at least eliminated a key suspect, making the investigation clearer. He tidied the documents on his desk, placing Zhao Zhiqiang's file at the bottom of the cabinet, then picked up the walkie-talkie, preparing to report the investigation results to Lu Chuan and begin a new chapter in the investigation.

When Zhang Hui's police car pulled up in front of Li Weiguo's rented apartment building, moss was creeping up the brickwork along the base of the walls. A faded blue curtain hung from the third-floor window, and the shadowy figures moving inside could be vaguely seen. "Move out!" he whispered into the walkie-talkie. Two officers rushed upstairs, the loud bang of the door startling the sparrows under the eaves. Li Weiguo was squatting on the ground welding a metal bucket, sparks from his welding torch splattering on the oil-stained floor. Seeing the police officers, he dropped the welding torch with a clatter.

The incandescent light in the interrogation room made Li Weiguo's face appear pale. Black grime was embedded in his fingernails, and an old wound on his right wrist was particularly noticeable under the light. "I don't know any deceased person," he said stiffly, his Adam's apple bobbing up and down. "I was working at the construction site on July 18th. My coworkers can testify to that." Zhang Hui slammed Li Weiguo's criminal record on the table. In 2018, he was sentenced to one year and six months for theft. The photo on his release certificate showed him 20 pounds thinner than he was now. "Your cousin's shell company received 50,000 yuan from Zhao Zhiqiang for steel. Why didn't they deliver the goods?"

Li Weiguo's eyes flickered, his fingers unconsciously digging into the wood grain of the table corner. "That was a business dispute, it has nothing to do with the murder," his voice suddenly rose, "My cousin ran away a long time ago, I haven't been able to contact him for six months!" Zhang Hui suddenly threw out a fingerprint comparison report, in which Li Weiguo's genetic type accounted for 30% of the mixed DNA under the victim's fingernails, "You say you don't know the victim, then why is there your DNA under his fingernails?" These words were like a stone thrown into calm water, and Li Weiguo's shoulders slumped instantly.

The construction site's attendance sheet was projected onto the interrogation room. Li Weiguo's name was indeed on the sign-in record for July 18th, but the handwriting was much more illegible than usual. "He left at three o'clock that afternoon," the foreman said, a cigarette dangling from his lips, his hard hat resting on the corner of the table. "He said his mother was sick and needed to go to the hospital. I saw he didn't look well, so I granted him leave." Hospital records showed that Li Weiguo's mother did indeed visit a doctor at four o'clock on July 18th, but the diagnosis was just a common cold. "He stayed at the hospital payment counter for less than half an hour before leaving; the surveillance footage can prove it."

Zhang Hui retrieved Li Weiguo's call records. At 5:02 PM on July 18th, he made a 47-second call to an unknown number. "Who is this?" He pushed the call log in front of Li Weiguo, whose Adam's apple bobbed violently: "A scrap collector, asking if I had any scrap metal to sell." But the technicians traced the number to the owner of a scrap metal recycling station, who confirmed that Li Weiguo had indeed sold a pile of scrap steel bars that day. "He came looking flustered, saying he had to go back to his hometown and was in a hurry to get rid of the goods, so he offered a very low price."

When the DNA comparison results between Li Weiguo and the deceased's whole genome came out, Zhang Hui was going through his bank statements. Only 2 out of 16 STR loci matched, with a paternity index of 0.01, completely ruling out blood relation. "The scrap steel bars you sold on July 18th, were they 12mm?" Zhang Hui suddenly asked. Li Weiguo's pupils contracted sharply. "Where did those steel bars come from?" His psychological defenses completely collapsed, and he squatted on the ground, burying his face in his hands: "I stole them from the construction site… but I really didn't kill anyone. I went home after selling the steel bars that day; the neighbors could see me!"

Neighbors' testimonies corroborated Li Weiguo's account. At 7 PM on July 18th, someone saw him buying soy sauce at the convenience store downstairs. "He was carrying a black plastic bag, saying it was medicine for his mother," the store owner said, flipping through the ledger. "The transaction record shows 7:15 PM, and he hasn't come out since." This period completely missed the timeframe of the deceased's death. Zhang Hui crossed out Li Weiguo's name, adding a note next to it: "Alibi available, DNA evidence excluded, no connection to the deceased." (End of Chapter)