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

Wang Shuai stood at the entrance of the apartment building and verified with Zhang Huaide. Zhang Huaide nodded slowly and replied in a hoarse voice, "Yes...it's right here. The night before the incident, before I left home, I changed into a green jacket and size 43 sneakers, and I also put a mask in my pocket."

Technicians immediately went forward to conduct a supplementary investigation of the changing location Zhang Huaide mentioned. Inside the wardrobe of his bedroom in room 502, they confirmed again that the green polyester fiber jacket matched perfectly with the green fiber sample extracted from the scene. They also found a pair of size 43 sneakers in the corner of the balcony; the mesh pattern on the soles perfectly matched the sneaker print characteristics extracted from footprint point 1 at the scene. A small amount of unwashed mud remained on the edges of the shoes, which, after preliminary comparison, matched the soil composition around the drainage ditch in the Jianshe Road community. "After you changed your clothes, how did you get to Zhang Feng Road's patrol area?" Wang Shuai continued to press. Zhang Huaide lowered his head and said, "After I changed my clothes, I walked out of the back gate of the community, along Xingfu Road all the way to the entrance of Xingfu Community, where I waited for Zhang Feng Road's patrol to come."

The escort team then proceeded to the entrance of Xingfu Residential Area. The entrance was already cordoned off, and technicians had marked the surveillance camera positions near the convenience store. "Zhang Huaide, when you were waiting for Zhang Fenglu here, did you enter this convenience store?" Wang Shuai asked, pointing to the store next door. Zhang Huaide glanced at the store and nodded, saying, "Yes, I went in. I was a little thirsty, so I bought a bottle of mineral water, paid, and came out, continuing to wait at the entrance." The technicians immediately retrieved the convenience store's surveillance footage and compared it with the previously extracted footage of Zhang Huaide entering the store at 9:15 PM the night before the incident, confirming that his account matched the surveillance record.

"What did you do after you saw Zhang Fenglu?" Wang Shuai led Zhang Huaide to the patrol route at the entrance of the residential area, the starting point where the surveillance footage showed Zhang Fenglu being followed. Zhang Huaide's body trembled slightly as he recalled, "Around 10:30 p.m., I saw Zhang Fenglu wearing a gray security guard T-shirt and dark blue work pants, walking along the patrol route at the entrance of the residential area. He was carrying a flashlight, shining it around as he walked. I quickly put on a mask and followed him about 10 meters behind, along his patrol route." He paused and added, "I knew he was going to the Jianshe Road community next, and the drainage ditch behind Building 3 there was a blind spot for the surveillance cameras, so I planned to act there."

Technicians immediately investigated the starting point of the tailing as described by Zhang Huaide. Although the ground was made of cement and no obvious footprints were left, a blurry shoe print was found under a sycamore tree by the roadside under the illumination of a multi-band light source. After extraction, it was compared with Zhang Huaide's sneaker print and the characteristics were confirmed to match, further confirming his tailing behavior. Subsequently, the escort team proceeded along the patrol route of Zhangfeng Road towards Jianshe Road Community. When passing through the passage between Xingfu Community and Jianshe Road Community, Zhang Huaide stopped and said, "When I followed him here, he seemed to notice something and looked back. I quickly hid behind a tree next to me. He didn't see me and continued walking." Technicians immediately examined the sycamore trees on both sides of the passage. On the trunk of one of the sycamore trees, they found a fresh friction mark, similar to the transverse friction mark extracted from the trunk of a sycamore tree in the middle of the investigation area at the scene. It was speculated that it was formed by the friction between Zhang Huaide's body and the tree trunk when he hid. A trace fiber sample was extracted from the tree trunk, and preliminary testing showed that it was consistent with the fiber composition of Zhang Huaide's green jacket.

Continuing for about 50 meters, they arrived at the core crime scene behind Building 3 of the Jianshe Road community—the drainage ditch area. The cordon had already been set up, and technicians had placed markers at various trace points, including the outermost footprint point 1, the middle footprint points 1-3, the middle tire track point 1, and various evidence extraction points in the core area. As Zhang Huaide reached the soil area north of the drainage ditch, his pace noticeably slowed, his eyes filled with fear. Seeing this, the bailiffs immediately stepped forward to steady him. "Zhang Huaide, what did you do here?" Wang Shuai pointed to the outermost footprint point 1, the location where the size 41 rubber boot print was extracted.

Zhang Huaide took a deep breath and slowly said, "When I followed him here, I saw Zhang Fenglu inspecting the environment around the drainage ditch. When he bent down to check the weeds in the ditch, I went around to this spot behind him, ready to take action. Because the ground here is relatively soft, I was worried about leaving my sneaker prints, so I took out the rubber rain boots I had prepared in advance from my pocket and quickly put them on." He pointed to his feet and added, "These rain boots are size 41, which I bought at a hardware store before. I usually wear them on patrol days in the rain, and I specifically put them in my pocket to bring with me before the incident." The technicians immediately compared the plaster model of the No. 1 footprint extracted from the scene with the size 41 rubber rain boots found in Zhang Huaide's home. The spacing of the horizontal stripes on the tread of the rain boots was exactly the same as the spacing of the stripes on the plaster model, both being 0.8 centimeters, and the wear was relatively light, which was consistent with the previous speculation that the shoes were "new or rarely used."

"After you put on your rain boots, how did you attack Zhang Fenglu?" Wang Shuai led Zhang Huaide to the earthen slope on the south side of the drainage ditch, where the mid-distance footprint and tire track points were located. Zhang Huaide's voice was choked with sobs as he said, "After I put on my rain boots, I quietly walked up behind Zhang Fenglu, and when he wasn't paying attention, I suddenly reached out my right hand and strangled him from behind, while covering his mouth with my left hand to prevent him from making a sound. He was startled and dropped his flashlight, then started struggling desperately." As he spoke, he gestured with his hands to demonstrate the strangulation motion, "I used my elbow to brace against the back of his neck, and tightened my grip with both hands, dragging him towards the drainage ditch. He struggled fiercely, kicking his feet wildly on the ground, leaving many messy footprints, and even trampling down the weeds nearby."

Technicians immediately pointed to footprints 1-3 in the middle distance, indicating to Wang Shuai that Zhang Huaide's description of "messy footprints" perfectly matched the three different types of shoe prints extracted from the scene. The rain boot print at footprint 3 in the middle distance matched the characteristics of footprint 1 in the outer perimeter, indicating it was left after Zhang Huaide changed into rain boots. The grid-like sneaker print at footprint 1 in the middle distance was left before he changed his shoes. The leather shoe print at footprint 2 in the middle distance was later verified to have been left by other residents passing by before the incident and was unrelated to the case. (End of Chapter)