Phi-Fic Chapter 1128 Expanding the Scope of On-site Investigation
Chapter 1128 Expanding the Scope of On-site Investigation
Xiao Yang's 3D scanner is building a scene model, and point cloud data is gradually taking shape on the screen. "There are obvious signs of shaking on the shelves around the body," he said, pointing to the screws on the third row of shelves. "The fixing screws are 2mm loose, and the spacing is 3mm wider than the other shelves, which means there must have been a struggle, and the suspect or the deceased bumped into the shelves." Five bearing boxes on the shelves have fallen to the ground, and the fingerprints on the packaging of one of them are completely different from the fingerprints on the warehouse spare key.
As Xiao Wang closed the notebook, Li Zhifeng was still praising Zhang Jianguo. "Old Zhang is just too meticulous," he said, tears dripping onto the words "material requisition dispute," "but he's incredibly kind to us old buddies. Last month, when my grandson was sick, he even gave me five hundred yuan." Xiao Wang noticed fresh oil stains on Li Zhifeng's cuffs, consistent with the oil composition on the warehouse floor, but his shoe prints didn't match the size 43 shoe prints found at the scene, temporarily ruling him out as a suspect.
As the first rays of sunlight shone through the warehouse's transom window onto the body, Xiao Yang and Xiao Sun's investigation had already lasted three hours. An undisturbed door lock, a missing bearing, deliberately damaged surveillance cameras, a size 43 diamond-patterned shoe print, a half-broken bearing with impact marks, a cut power cord… these clues were like scattered beads, not yet strung together. Li Ming, looking at the crime scene model on the screen, suddenly pointed to drag marks next to the body: "These marks are a straight line from the doorway to the body, but there's a 90-degree turn in the middle, indicating that the suspect hesitated while dragging, or was unfamiliar with the warehouse environment."
The cicadas began to chirp outside the warehouse, and the investigators moved among the shelves, their notebooks filled with numerous suspicious points. Without a forensic pathologist, all judgments were based on visible physical traces, which silently recounted the struggle, dragging, and death that had occurred in the warehouse the previous night, waiting to be pieced together to form the complete truth.
Li Ming's rubber boots crunched over a withered leaf on the cement ground at the warehouse entrance, morning dew condensing into fine beads on the boots. "Expand the search area to the entire factory area," he said in a deep voice into the walkie-talkie, his fingertip tracing a semi-circle on the survey map. "The perimeter of the walls, the parking lot, the drainage ditches—not an inch can be missed." Xiao Yang, who was squatting on the ground adjusting the plaster powder mix, immediately straightened up upon hearing this, dark sweat stains already soaking the back of his blue survey uniform: "Understood. Focus on tracking the size 43 diamond-patterned shoe print at the scene."
Carrying a multi-band light source, Xiao Sun led the way to the parking lot. The morning light slanted through the steel frame of the factory, casting crisscrossing shadows on the ground. "There's a broken shoe print here," he suddenly stopped next to an abandoned forklift. Switching the light source to 380nm ultraviolet light, a pale blue fluorescent outline appeared on the cement ground. "The forefoot pressure surface accounts for 60%, the stride width is 13cm, slightly wider than in the warehouse, but the diamond pattern is exactly the same." He measured the stride length at 72cm with a ruler. "Estimating the height to be 175±3cm, the left leg bears 15% more weight than the right leg, which matches the characteristic of 'more severe wear on the left forefoot' in the warehouse."
Xiao Yang had already prepared the plaster powder; the milky white slurry was foaming in the plastic basin. "Take this shoe print off," he said, sprinkling fine sand into the mold to increase its hardness. "Watch out for the cracks along the edges. Cement doesn't absorb well, so wrap it in plastic wrap immediately after it hardens." He suddenly pointed to the forklift chassis, where a brown fiber hung from the metal bracket. "Extract this, and use a Raman spectrometer to analyze its composition. It looks like work pants material."
As the two searched along the base of the wall, Xiao Sun's metal detector suddenly beeped rapidly. He crouched down, parted the overgrown weeds, and revealed a rusted bearing casing, its dark red stains gleaming in the sunlight. "Model 6205, the same batch that went missing from the warehouse," he said, dabbing the stain with a sterile cotton swab. "But the bloodstains have dried, and the serum protein test is weakly positive, so it might have been washed away by rain." Xiao Yang suddenly noticed that the soil next to the bearing had been disturbed. "Use a Luoyang shovel to take three soil samples and see if there's a deeply buried murder weapon."
“Look at these climbing marks,” Xiao Sun pointed to the barbed wire at the top of the wall. Two wires were bent in a V-shape, with a piece of dark blue fabric hanging from the tip. “The bending angle is 45 degrees, and the distance between the stress points is 30cm, which is the width of an adult’s two hands.” He asked Xiao Yang to measure it with a protractor. “The degree of damage to the oxide layer on the wire indicates that it was formed within 12 hours, which matches the time of the crime.” The fabric fragment fluoresced under ultraviolet light, and preliminary testing showed that it matched the cotton-polyester blend of Zhang Jianguo’s work pants. “It must have been caught when dragging the body.”
Dark green sewage filled the drainage ditch on the east side of the warehouse. When Xiao Yang used a long-handled net to retrieve it, the mesh caught a black plastic bag. The knot at the bag's opening was a "clove knot," a common knot used by fishermen. After untying it, half of a steel pipe was exposed, the rust on its surface leaving a brownish-red mark on the survey gloves. "3cm in diameter, 60cm in length," Xiao Sun measured the pipe wall with calipers. "There are fresh wiping marks on the inside, and the STR typing of the extracted skin tissue fragments matches Zhang Jianguo's, but there are no fingerprints on the outside—they were deliberately wiped off."
“This steel pipe weighs 1.2 kg,” Xiao Yang said, weighing it in his hand. “The kinetic energy from swinging it would be just enough to cause a depressed skull fracture in the victim, matching the forensic doctor’s initial assessment of the murder weapon’s specifications.” But he suddenly frowned. “However, the bearings were the ones missing from the warehouse. This steel pipe seems more like it was brought in from outside, indicating that the suspect may have prepared two types of murder weapons.” Xiao Sun was examining the oil stains on the steel pipe. The peak values on the infrared spectrum matched the machine oil on the warehouse floor perfectly. “He was in the warehouse for at least half an hour; the steel pipe got oil on it.”
When the two returned to the warehouse, technicians were performing a 3D scan on the third row of shelves. "The scratches on the shelf uprights are 0.3mm deep," Xiao Yang pointed to the point cloud model on the screen, "showing a slanted distribution, higher on the left and lower on the right, which matches the angle of a right-handed blow with a blunt object—perfectly corresponding to the shape of the wound on Zhang Jianguo's left forehead." He had Xiao Sun check the shelf screws. "The torque value of the fixing screws is 25 N·m, 5 N·m lower than the standard value, indicating that they loosened after the impact; the struggle must have occurred here."
Xiao Sun's attention fell on the iron bars of the ventilation duct. The bars were spaced 15cm apart, just enough for an arm to slip inside. "There are two spots where the paint has peeled off," he observed the cross-section under a microscope. "One is fresh, in a torn shape; the other has an oxide layer, indicating an older damage." He suddenly noticed a blurry fingerprint on the inside of the bars. "After developing it with super glue, the center of the fingerprint is whorl-shaped, but there are only four details, which doesn't meet the criteria for inclusion in the database. It's likely left by the suspect when they reached in to damage the surveillance."