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

As Lu Chuan closed the file, the metal clasp made a crisp sound: "The man in the black trench coat must be found within 48 hours. He is the key to unlocking all the mysteries." The sound of chairs rubbing together filled the conference room; everyone knew that this race against time had only just begun.

The glass door of Yuantu Technology slid open slowly in Lu Chuan's palm, and a blast of cold air, carrying the distinctive smell of printer toner, rushed out. The receptionist's carefully applied lipstick cracked at the corner of her mouth the instant she saw the police badge. Lu Chuan flashed his badge, his gaze sweeping over the gilded slogan on the wall: "Technological Innovation, Integrity First"—ironically, he was currently clutching in his hand the company's nine administrative penalty records from the past three years, obtained from the business registration authority.

"The smart city project that Zhou Mingguang was in charge of?" The technical director adjusted his gold-rimmed glasses, the swivel chair scraping against the carpet with a harsh creak. "He did take some source code with him before he left, but that was his personal achievement during his tenure, and the company has already resolved it through legal channels." Lu Chuan noticed the rhythm of the other man's tapping on the table, the wedding ring on his ring finger making a regular clicking sound—a typical psychological defense mechanism.

The musty smell in the archives room was almost palpable. Lu Chuan squatted in front of the dusty filing cabinet, his flashlight beam sweeping across the "2023 Smart City Project" label. When he opened file folder number 17, several yellowed test reports fluttered to the floor, with the words "Execute as originally planned" annotated in red next to the cement compressive strength data. Technician Xiao Lin suddenly pointed to a corner: "Team Leader Lu, Zhou Mingguang's approval signature is here!"

However, when the data was sent to the quality inspection department for analysis, the experts' conclusion was like a bucket of cold water: "Although the data is suspected of false advertising, it does not meet the standards for criminal prosecution." Lu Chuan stared at the cement sample under the microscope; the substandard particles lay quietly on the slide, just like the gradually cooling clue in his hand.

The individual meetings with company executives were more like a protracted tug-of-war. The CFO slammed bank statements on the table, every transaction clearly marked; the marketing manager pulled out cooperation agreements, confidently guaranteeing that all projects were legal and compliant. When Lu Chuan mentioned the 50 yuan transfer Zhou Mingguang made before leaving the company, the air conditioner in the conference room suddenly roared, drowning out everyone's breathing.

“That’s his non-compete compensation!” The general counsel finally broke the silence, but when Lu Chuan asked to see the original agreement, he claimed the document was locked in a safe. This detail alerted Lu Chuan, and he immediately applied for a search warrant. However, when the officers opened the safe, they found only a few boxes of expired mooncakes and a half-broken wrench—the same model as the tool missing from the murder scene, but it was rendered useless as evidence due to the numerous fingerprints covering its surface.

During his seven-day investigation at Yuantu Technology, Lu Chuan filled three notebooks. He looked at the newly added relationship diagrams on the whiteboard; the lines representing business disputes and clues to the murder case never seemed to intersect. When the final investigation report was placed on the table, the charges of commercial bribery and false advertising all pointed to administrative violations, not criminal offenses.

On a sudden downpour at dusk, Lu Chuan stood beneath the Yuantu Technology building, rainwater trickling down his umbrella. He recalled the deliberately altered quality inspection report in the archives, the shifty eyes of the executives, and suddenly realized that this investigation might have touched upon some deeper secrets—secrets temporarily shrouded in the gray areas of the law, unable to become the key to unlocking the truth of the murder case. He stuffed his soaked notebook into his coat, turned, and walked towards the police car. With the sound of tires crunching through the puddles, another clue sank into the darkness.

The refrigerator in the forensic lab hummed softly. Zhang Kai's double-gloved fingers hovered above the centrifuge, the blue blood sample forming clear layers in the centrifuge tube. When the automated sequencer produced the final comparison report, he stared at the red words "99.99% probability of ruling out paternity" on the screen, and suddenly felt as if the lab's temperature control system had malfunctioned—cold sweat instantly soaked through his white lab coat.

“Test again, using Y-chromosome STR typing.” Zhang Kai’s voice trembled without him even realizing it. Intern Xiao Chen retrieved the sample again, the pipette tip trembling slightly on the slide. She knew what this result meant: all the investigations surrounding “Zhou Mingguang” over the past 72 hours might have been based on flawed evidence. The results of the second comparison came back two hours later, still marked by glaring red exclusion markers; not even a single match was found among the 16 loci on the autosomes.

Zhou Mingguang's wife had been sitting in the reception room for three whole hours, her fingers repeatedly tracing her husband's photo—the man in the picture was smiling on the beach, holding a coconut, with the azure sea and sky of the Maldives as the background. "Officer, are you sure you haven't made a mistake?" Her voice was choked with tears as she pushed the chat history on her phone in front of Zhang Kai. "He video-chatted with me yesterday, saying he'd come back next month to celebrate our daughter's birthday." Zhang Kai noticed that the man in the video screenshot was wearing a wide-brimmed hat and constantly covered his forehead with his hand, while the deceased had a noticeable osteoma on his forehead, a feature completely invisible in the video.

More crucial evidence came from dental records. Zhang Kai reviewed Zhou Mingguang's dental filling records from 2018. The digital model from the Municipal Stomatological Hospital showed that his upper right second molar had a zirconia all-ceramic crown, while the deceased's corresponding tooth had an amalgam filling. The two restoration methods showed drastically different density shadows on X-rays. "The translucency of an all-ceramic crown is 82%," Zhang Kai pointed to the comparison image, "while amalgam is completely opaque; this is a physiological characteristic that cannot be faked."

When Zhang Kai laid out the DNA profile in front of Zhou's wife, she suddenly covered her mouth, tears streaming down her face: "Then who is that person in the video? Where is Mingyuan?" She broke down, incoherently recounting her husband's unusual behavior after leaving his job: "He said the company had a secret project in Southeast Asia, told me not to ask too many questions, and even changed the property deeds to my name." These details exploded in Zhang Kai's mind—if the deceased wasn't Zhou Mingguang, then where was the real Zhou Mingguang? And who was the person in the video wearing the wide-brimmed hat?

The technical department brought even more perplexing news: the DNA from the skin tissue under the deceased's fingernails perfectly matched the fingerprints on the coffee cup found in Zhou Mingguang's office drawer. "This means the two definitely had close contact, perhaps even a physical altercation." Zhang Kai stared at the superimposed DNA maps; the deceased's genetic sequence resembled an unfamiliar river, yet in a certain segment, it faintly overlapped with Zhou Mingguang's genetic markers. "They might know each other, but they are definitely not the same person." (End of Chapter)