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

"No!" he suddenly burst out, slamming his shackled hands on the table. "We just... we just helped a friend tow his car!" This statement was clearly a hastily fabricated story, and even he himself didn't believe it. Zhang Hui pushed a high-resolution photo of the van's door in front of him. The pry marks from the steel pipe were clearly visible under the bright light, and the metal shavings at the edges, after testing, matched the composition of the steel pipe in Zheng Baohai's toolbox perfectly. "This mark," Zhang Hui circled in red on the photo, "was left when you pried open the door with the steel pipe. The angle was 37 degrees, perfectly matching the bending angle of the crowbars you commonly use on your construction site."

Zheng Baohai's fingers began to twitch uncontrollably, his nails digging deep into the calluses on his palms. He suddenly remembered something, a glimmer of hope flashing in his eyes: "That day I went to help Li Nana get something. She was arguing with Sun Qiang and asked me to help her out..." Before he could finish speaking, Zhang Hui interrupted him, pulling up Li Nana's call records. A recording of a call from 5:10 pm on July 18th suddenly rang out in the interrogation room: "Sun Qiang, come to the woods behind the building materials market. I'm returning your graduation certificate to you."

"Graduation certificate?" Zhang Hui pressed the pause button; the static from the recording still echoed. "Sun Qiang's graduation certificate has long been with his wife. Who do you think this lie can fool?" He suddenly slammed a DNA report in front of Zheng Baohai. Skin tissue fragments from under Sun Qiang's fingernails matched Zheng Baohai's genetic profile perfectly. "He grabbed you before he died, didn't he?" Zhang Hui's voice pierced Zheng Baohai like an ice pick. "Just as you were hitting him on the head with the steel pipe, he grabbed your arm!"

These words were like a key driven into Zheng Baohai's taut nerves, causing his psychological defenses to crumble instantly. His forehead pressed against the cold table, the chains leaving red marks on his wrists: "Li Nana made me do it..." His voice was choked with sobs, spittle splattering onto the interrogation record, "She said Sun Qiang owed her more than 80,000 yuan, and that he had hidden some money when they divorced. We just wanted to scare him and get him to give us another 50,000 yuan..."

He suddenly looked up, his eyes bloodshot, as if trying to spill every detail: "When we met in the woods, Sun Qiang had just shown Li Nana the transfer record for the last compensation payment, saying that we were even now. Nana suddenly said that he had a bank card in his wallet, and that there must be money in it, and told me to rob it. When Sun Qiang resisted, I... I grabbed a steel pipe from the trunk and smashed it over his head." Zheng Baohai gestured with his fingers, indicating the arc of the swinging steel pipe. "When he fell, his head hit a rock, and blood gushed out immediately."

Zhang Hui gestured for the recorder to speed up, the pen tracing messy arcs on the paper. "How did you handle the body?" he pressed, Zheng Baohai's shoulders still trembling violently. "Was the van prepared beforehand?" Zheng Baohai nodded, his Adam's apple bobbing. "Nana said she knew about that abandoned parking lot all along, and there was an unwanted van inside. When we carried Sun Qiang in, his wallet fell out of his pocket, and I just stuffed it in… Later I found there was only three thousand yuan in cash and this tattered card inside."

He suddenly pounded his thigh with his handcuffed hands, the clanking of the shackles echoing in the interrogation room: "I went back to the scene to throw the wallet back, so that if it was discovered, I could say it was robbery and murder, and that it had nothing to do with Nana..." This statement exposed his collusion with Li Nana. Zhang Hui immediately had the technical team compare the details of the two men's statements, and sure enough, they found many contradictions in the route of the body disposal and the handling of the steel pipe, confirming Zheng Baohai's attempt to take the blame alone.

When Zhang Hui presented the recording recovered from the dashcam, Zheng Baohai slumped completely in the interrogation chair. “When Sun Qiang said ‘Don’t bother me anymore,’ I was behind the tree holding a steel pipe,” his voice was hollow like a deep pool. “Nana said, ‘Look what this is,’ actually she wanted him to turn around and look at me… My mind went blank; I just thought, ‘Hit it, hit it and I’ll get money…’” He suddenly covered his face, the sobs escaping through his fingers growing louder. “I never dared to spend that three thousand yuan; I hid it under the bed, and it’s still there…”

As darkness fell outside the interrogation room, Zheng Baohai's confession continued. He detailed how he pushed Sun Qiang's Lavida into the ditch, how he covered the tire tracks with branches, and even remembered the exact location where he threw the steel pipe into the scrap yard. Zhang Hui watched the increasingly dense handwriting on the clerk's pen and suddenly felt the interrogation room lights were particularly glaring—the red light, ignited by greed, ultimately illuminated not only the faces of the two murderers, but also the ugliest wrinkles deep within human nature.

On the morning of the seventh day after the incident, dark clouds pressed the sun low, and the iron gate of the abandoned parking lot creaked horribly as it was dragged along by police cars. Li Nana's red dress was faintly visible beneath her prison uniform, and as she was carried forward by two policewomen, the shackles on her ankles left two white streaks on the gravel road. Zheng Baohai walked behind, his head drooping almost to his chest, his work pants still stained with unwashed mud at the knees—later confirmed by technicians to be identical in composition to the soil in the parking lot.

“This is it.” Li Nana’s voice trembled uncontrollably as she pointed to the grove behind the building materials market. The grass there was still bent over, and when photographed with a multispectral camera, the red fluorescence it displayed at 450nm matched perfectly with the fluorescence intensity of the fibers on her dress. “At 5:40 pm on July 18th, I called Sun Qiang to come and pick up my graduation certificate. He drove to this grove and parked under that old locust tree.” She suddenly squatted down, picking at the grass roots in the soil with her fingers. “When he got out of the car, he laughed at me, saying, ‘Finally, I’m not bothering you anymore,’ without even seeing Zheng Baohai behind the tree.”

Technicians immediately began their investigation under the old locust tree. The metal detector beeped rapidly, and they unearthed half a plaster model of a size 43 shoe print from 30 centimeters deep in the soil—a pattern that perfectly matched the sole of Sun Qiang's ride-hailing driver's shoes. "There are fresh signs of soil disturbance here," Yang Lin said, using a probe to break up the topsoil. "The humus content here is 15% lower than the surrounding area, which is consistent with the characteristics of someone standing here recently, and it matches the pressure distribution calculated based on Zheng Baohai's height and weight."

As Zheng Baohai was led to the center of the woods, he suddenly struggled violently, the chains leaving red marks on the wrists of the escorting officers. "I didn't start it!" His shout startled crows in the treetops. "Sun Qiang pushed Li Nana first, so I..." He was interrupted by Zhang Hui, who pointed to a dent in the ground: "Where were you standing when you hit him with the steel pipe?" Tests on the soil at the dent revealed a calcium-to-phosphorus ratio consistent with Sun Qiang's skull, clearly indicating the point of impact to his head. (End of Chapter)