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

The second layer of evidence is entomological: 1.8cm long third-instar maggots and pupal shells were extracted from hair and clothing crevices. These maggots would take 5-6 days to mature at the current temperature, cross-validating with the characteristics of cadaver decomposition. The third layer of evidence is the stomach contents and drug metabolism: only brownish, pasty substances remained in the intestines, with no undigested food, consistent with an emptying state 8-12 hours after death. This matches the family's statement that they ate at home at 7 pm last Wednesday. Furthermore, no drug residues were detected in the stomach wall tissue, ruling out poisoning and further narrowing down the timeframe for natural death.

"The fatal wound and key injuries are the focus. Are there any clues that directly connect to the suspect?" Lu Chuan pressed, his finger hovering over the "Injury Analysis" page of the report, his brow furrowed slightly. Zhang Kai switched to the injury photos, his tone serious: "The fatal wound is a mechanical asphyxiation injury to the neck. There is a 0.8cm wide band-shaped indentation around the neck, with slight fibrous damage at the edges. A small amount of cotton fibers were detected at the skin rupture on the left side, suggesting that the weapon used was a soft, band-like object such as a towel or cloth strip. There is obvious bleeding in the neck muscle tissue corresponding to the indentation, a fracture of the greater horn of the hyoid bone, and mucus blockage in the trachea and bronchi, which are consistent with the typical pathological characteristics of death by asphyxiation. Furthermore, the direction of force on the indentation is 'backward to forward,' indicating that the suspect attacked Zhang Hao from behind, taking advantage of his unpreparedness to strangle him."

He added, "There are two additional injuries that need attention: First, an irregular 3×2.5cm wound between the 4th and 5th ribs on the left chest. The wound edges are contused, and black foreign matter inside the wound cavity was tested and found to be soil from a landfill. There are minor bone fractures on the surface of the ribs, but no bleeding at the wound site. Based on the degree of decomposition, it is judged to have been formed after death or near death. It is speculated that the body collided with garbage when the suspect disposed of the body, and there is no direct connection to the crime. Second, multiple abrasions on the right palm, black plastic fibers extracted from under the fingernails that are consistent with the composition of the plastic bag that wrapped the body, gray cement dust that is consistent with the composition of cement from a construction site, and a small amount of male skin tissue fragments whose DNA has been entered into the system. The nail of the left ring finger is broken. All of these are defensive injuries from the struggle before death, proving that Zhang Hao had physically resisted the suspect before being strangled. In addition, a silver metal fragment was embedded in the skin of the left wrist. After testing, it was found to be consistent with the metal buttons and chains found at the scene, confirming that it was a fragment of the bracelet he was wearing, which was most likely torn off by the suspect during the struggle."

Next, Yang Lin reported on the on-site investigation. The topographical map of the scene that popped up on the screen marked key traces in red and blue: "After expanding the scope of the investigation, three core findings need to be supplemented. First, three pieces of black plastic were extracted from the sewage outlet ditch of the landfill compression station. The material is completely consistent with the plastic bag used to wrap the body. One of the pieces has dark red stains on it, which are preliminarily identified as suspected bloodstains and a small amount of cotton fibers. The composition of the cotton fibers found on Zhang Kai's neck injury is the same. It is speculated that when the suspect wrapped the body, the plastic bag broke due to force, and the fragments and fibers fell off together. Moreover, the fibers are likely from the strip used in the crime."

Yang Lin switched to the next photo, which showed footprints and a metal button at the base of the wall: "Secondly, under an abandoned mattress at the base of the north wall, we found half a size 43 men's sneaker print. The toe prints were clear, and the soil it was covered in contained red paint particles that matched the paint composition of the wall near Zhang Hao's auto repair shop. Furthermore, the characteristics of the shoe print perfectly matched those of the shoe print previously found to the east of the body, further confirming that the suspect was 175-180cm tall and had been active around Zhang Hao's auto repair shop. The metal button next to the shoe print is made of brass plated with gold. After comparing its shape, it matched the edge curvature of the metal fragment on Zhang Hao's left wrist, confirming that it came from the same bracelet. It is speculated that the bracelet broke during the struggle, and the button fell here."

"Third, five parallel scratches were found on the conveyor belt surface in the waste sorting area. The length of these scratches was similar to Zhang Hao's height. Black plastic residue remained at the edges of the scratches, consistent with the material of the plastic bags. In a storage box next to the scratches, a crumpled tissue was found. The brown stains on the tissue were similar in color to the suspected bloodstains on the plastic fragments. Half a blurry fingerprint was also extracted and preliminarily compared, ruling out Zhang Hao's fingerprints." Yang Lin put away the laser pointer and added, "In addition, the 'Hongtashan' cigarette butt found at the scene was tested. The DNA from the saliva on the cigarette butt filter matched the DNA from male skin tissue fragments found under Zhang Hao's fingernails, confirming that the cigarette butt belonged to the suspect. The suspect's habit of chewing cigarette butts, the teeth marks on the filter, and the fact that only one-third of the cigarette butt was burned are corroborating evidence that this can serve as auxiliary features for subsequent identification."

Zhang Hui concluded by reporting the deceased's identity and related clues. A social relationship chart of Zhang Hao appeared on the screen, with red lines highlighting his conflict with Wang Hu: "Through interviews with people around Zhang Hao, we have identified key connections. First, the economic conflict: Zhang Hao's ledger shows that Wang Hu owed a total of 4800 yuan in car repair fees since three months ago. The last payment of 1200 yuan was marked 'unpaid' last Wednesday. Zhang Hao's cousin, Zhou Lan, confirmed that Zhang Hao had repeatedly urged Wang Hu to pay, but was refused each time. Wang Hu even threatened, 'If you keep urging me to pay, I'll make sure your shop goes out of business.' The two argued in front of the auto repair shop last Wednesday afternoon, witnessed by nearby shopkeepers."

"Secondly, the clues match up to last Wednesday evening at 8 PM. Li Mei, from Sister Li's Noodle Shop, saw Wang Hu wearing a black coat, driving an old white van to the auto repair shop. He talked to Zhang Hao at the door, and his mood was clearly unpleasant. Afterwards, Zhang Hao closed the shop and left with Wang Hu. This was Zhang Hao's last publicly known whereabouts. Li Baoku, the person who reported the incident at the garbage dump, said that around 10 PM last Wednesday, he saw a white van with a broken left headlight and abnormal engine noise parked at the entrance of the garbage dump, which highly matches the characteristics of Wang Hu's vehicle." Zhang Hui paused for a moment, then pulled up Wang Hu's basic information: "Wang Hu, male, 42 years old, construction contractor, 178cm tall, medium build, which matches the suspect's height characteristics; he owns a white van with license plate number: 京AXXXX8, registered 5 years ago, with multiple recent traffic violations, but no violations since last Wednesday, and the vehicle's whereabouts are unknown; in addition, Wang Hu works on construction sites and is in daily contact with cement and paint, which is consistent with the source of the cement dust and red paint particles found at the scene, providing him with the conditions to access the crime environment."

"Any clues about Wang Hu's disappearance and subsequent whereabouts?" Lu Chuan pressed, his fingers tapping rapidly on the table, clearly paying close attention to this lead. Zhang Hui nodded: "Wang Hu has been out of contact since last Thursday morning when he left the construction site citing 'emergency family matters.' His phone is switched off, and his bank account has had no transaction records for the past seven days." (End of Chapter)