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

“He had over 300 yuan in cash in the left pocket of his jacket, all in small change, so I put the money in my own pocket. Then I looked inside the car to see if there was anything else valuable. I saw that the glove compartment was open and there was an ID card, an operating permit, and a mobile phone inside. I wanted to take the phone too, but I was afraid that the phone could be tracked and you would find out, so I didn’t dare to touch it.”

“When I got out of the car, I specifically looked around and didn’t see anyone, so I quickly closed the car door. Because I was so flustered, I didn’t even lock the door, which is why the cleaning worker was able to easily open it later.” Deng Chengzong’s gaze turned towards the sidewalk. “After I got out of the car, I walked south along the sidewalk for about three meters. I felt a little uncomfortable, and when I looked down, I found some bloodstains on my clothes. It must have been blood from Zhang Tiancheng’s chest that got on me when he strangled me. I quickly wiped it off with my hand, and accidentally dripped a few drops of blood onto the edge of the green belt next to the sidewalk.” This perfectly matched the few dark red drops of blood found at the edge of the green belt about 5 meters away from the taxi during the on-site investigation. The subsequent examination by the technical department also confirmed that the bloodstains were indeed Zhang Tiancheng’s.

“I was terrified of being discovered, so I quickened my pace and walked south along Wanghe South Road. When I reached the intersection of Wanghe South Road and Xingfu Street, I looked around and saw no surveillance cameras, so I slipped into a nearby alley. I circled the alley a few times to make sure no one was following me before I calmed down.” Deng Chengzong paused, then continued, “I didn’t dare take the belt that strangled Zhang Tiancheng with me. In the alley, I was afraid the belt would become evidence, so I found a trash can and threw it in. That trash can was in a small alley south of the intersection of Wanghe South Road and Xingfu Street; it was a green plastic trash can.”

Wang Shuai immediately arranged for his team to search for the belt at the location Deng Chengzong had described. He then pressed further, "Did you smoke after you got into Zhang Tiancheng's taxi? During the on-site investigation, we found a 'Chunghwa' cigarette butt under the driver's seat; it had your DNA on it." Deng Chengzong nodded. "Before getting in the car, I smoked a 'Chunghwa' cigarette. Because I was nervous, I only smoked half of it before putting it out and putting it in my pocket. After getting in, I was still nervous, so I took out the cigarette butt, wanting to take another puff, but I was afraid Zhang Tiancheng would find it, so I just threw it under the seat. I didn't expect you to find it too."

"During the on-site investigation, we extracted several black hairs and a small amount of white synthetic fibers from the gap in the back seat of the taxi. After testing, these hairs and fibers all came from you. What is your explanation for this?" Yang Lin stepped forward and asked. Deng Chengzong thought for a moment, "When I sat in the right rear seat, a few hairs may have fallen onto the seat. As for the white synthetic fibers, they should be from the black hooded sweatshirt I was wearing. The lining of that sweatshirt is made of white synthetic fiber, and it may have gotten into the gap in the seat." The technical department later tested the black hooded sweatshirt extracted from Deng Chengzong's rented room and confirmed that its lining was indeed white synthetic fiber, completely consistent with the fiber composition extracted from the scene.

To further verify Deng Chengzong's confession, Wang Shuai asked him to describe in detail the actions and force used to strangle Zhang Tiancheng. Deng Chengzong gestured and said, "I put the middle part of the belt around Zhang Tiancheng's neck, grabbed both ends of the belt with both hands, and pulled hard to both sides, creating a crisscrossing force. Because I was sitting in the right rear seat, I used more force on the left side, and the strangulation was also stronger." This perfectly matched the characteristics found during the forensic autopsy: "faint, dark purple ligature marks appeared on the front and sides of the deceased's neck, horizontal in shape, encircling the neck, with the left ligature mark being deeper and the right side slightly shallower." The forensic doctor also deduced at the time that the murder weapon was likely a soft, uniformly wide strap, completely consistent with the black leather belt Deng Chengzong described.

"When you strangled Zhang Tiancheng, did he show any signs of resistance? Like kicking his arms and legs or shouting for help?" Zhang Hui asked. Deng Chengzong shook his head. "He did resist at first, grabbing the belt with both hands and twisting his body, but because I used my knee to press against his back, he couldn't turn around or make a sound, only 'woo-woo' sounds. After about a minute or two, his resistance weakened and eventually he stopped moving." This was completely consistent with the forensic autopsy findings that "the deceased had patchy bleeding in the middle of the sternocleidomastoid muscle and a slight bone fracture at the upper corner of the thyroid cartilage." The forensic doctor also deduced at the time that the deceased's neck muscles contracted violently during the strangulation, or that the suspect pressed or pulled on the neck forcefully, causing these injuries.

At this moment, the team members who went to find the belt reported back that they had found a black leather belt near the trash can mentioned by Deng Chengzong. The team members immediately brought the belt back to the scene and handed it over to Yang Lin for preliminary examination. Yang Lin shone a searchlight on the belt and found a small amount of dark red bloodstains. He then used a cotton swab to collect a bloodstain sample, marking it as "Bloodstain Sample No. 1 at the Scene of Identification," and prepared to take it back to the technical department for testing. When Deng Chengzong saw the belt, his body visibly trembled, and his eyes were filled with fear. "It's this belt, the one I used to strangle Zhang Tiancheng."

Wang Shuai had his teammate place the belt in front of Deng Chengzong so he could confirm the details. "The buckle on this belt is silver with a 'CK' logo. I bought it for a little over two hundred yuan. Because it's been used for several years, the edges are a bit worn, especially around the buckle," Deng Chengzong said, pointing to the buckle and edges. Yang Lin examined it carefully and found that the buckle was indeed silver with the "CK" logo, and the buckle area showed obvious signs of wear, perfectly matching Deng Chengzong's description.

Deng Chengzong then detailed his escape route after committing the crime: "After I came out of the alley at the intersection of Wanghe South Road and Xingfu Street, I walked east along Xingfu Street. When I reached Changsheng Road, I saw a 24-hour convenience store, so I went in and bought a bottle of mineral water and a pack of cigarettes to calm myself down. I paid with WeChat Pay. The shop owner was a middle-aged woman, and I didn't dare look up at her. After buying the things, I walked north along Changsheng Road. When I reached the intersection of Binhe East Road and Jiankang Street, I disappeared into the nearby urban village because there were fewer surveillance cameras there, making it less likely to be discovered." (End of Chapter)