eurekapd Chapter 1129 Zhang Kai performs an autopsy
Chapter 1129 Zhang Kai performs an autopsy
“The cut on the power cable is crucial,” Xiao Yang said, holding up the severed cable. Under a magnifying glass, the cut was a clean, slanted slice. “The angle was 37 degrees, and the blade width was 2mm. It was cut with a professional electrician’s knife, not ordinary scissors.” He had the technicians analyze the metal composition. “The trace amounts of tungsten carbide powder remaining at the cut came from a tool with a hardness of HRC58, which is very common in the machine repair workshop of the bearing factory.” Xiao Sun added, “The person who sabotaged the surveillance system knew the wiring layout and knew the main unit was in a corner of the warehouse. They were definitely an insider or someone extremely familiar with the factory area.”
When the investigation expanded to the machine repair workshop, Xiao Sun found an electrician's knife in the toolbox, the blade width of which perfectly matched the cut of the power cord. "But the fingerprints on the handle belong to Lao Wang, the machine repairman," he said, shaking his head after comparing the fingerprints. "Lao Wang was at the hospital last night with someone, so he has an alibi." Xiao Yang was checking the workshop's attendance sheet. The sign-in record for July 14th showed that repairman Li Jun left work two hours early. "That's the Li Jun who argued with Zhang Jianguo. A pair of size 43 safety shoes is missing from his locker."
The soil sample test results from the drainage ditch came back. Xiao Yang frowned as he looked at the report: "The concentration of bearing steel in the soil is 0.03%, only slightly higher than the background value, indicating that the missing bearing wasn't thrown into the ditch." Xiao Sun suddenly noticed a fresh scratch on the wall of the drainage ditch in the parking lot. "The moss here has been rubbed off, covering an area of 20x15cm, which matches the contact area of an adult male's knee. The suspect may have knelt here, perhaps hiding something." But after scanning the area three times with a metal detector, they only found a rusty nail.
“The cadence analysis of the shoe prints is complete,” Xiao Yang pointed to the data chart. “From the warehouse to the wall, the cadence increased from 80 steps/minute to 110 steps/minute, indicating that the suspect accelerated when leaving, but the stride length remained stable at 72cm, showing no panic, as if there was a clear escape route.” Xiao Sun suddenly remembered something, “Although the surveillance cameras outside the wall are broken, the traffic cameras at the intersection should have captured the vehicles. 37 motorcycles passed by in the past 12 hours, 5 of which were blue Qianjiang brand motorcycles—which matches the ‘motorcycle sound’ that Li Zhifeng mentioned.”
The investigation continued until noon, and Xiao Yang's notebook was already filled with 47 clues: the pressure distribution curve of the size 43 diamond-patterned shoe print, the warp and weft density parameters of the brown fiber, the direction of the wiping marks on the inner wall of the steel pipe, the microscopic photograph of the power cord cut... But none of them directly pointed to the suspect. "The most troublesome thing is that missing bearing," Xiao Yang marked a question mark in red pen on the ledger, "It's either the key murder weapon or it contains information about the suspect. If we can't find it, we've lost an important lead."
Xiao Sun put the last fiber sample into the evidence bag. The label read, "Taken from fence wire, polyester fiber, 150D/36F." "This type of fiber is commonly used in safety nets for construction workers," he said, analyzing the spectral data. "Combined with left-handed characteristics and familiarity with the factory environment, the suspect is likely a male with a construction or mechanics background, around 175cm tall, and with an old injury to his left leg." But these were all just profiles, lacking concrete evidence.
The two men sat on the steps outside the warehouse, twirling water bottles in their hands. In the distance, a tower crane slowly turned, casting moving patches of light on the ground. "All the clues are like looking through a fog," Xiao Yang said, gazing at the woods beyond the wall. "Shoe prints, fibers, steel pipes—every detail points to someone inside, yet we're missing the final piece of concrete evidence." Xiao Sun's phone suddenly vibrated; it was a message from the technical team: "The purchase record for the safety shoes shows that Li Jun bought a pair of size 43 diamond-patterned shoes three years ago, but reported them lost six months ago."
The news was like a pebble thrown into the calm investigation log. Xiao Yang abruptly stood up: "Check the surveillance footage after the missing shoes were reported! See who took them!" Sunlight streamed through the warehouse's transom window, casting bright spots on the bloodstains on the floor. The scattered clues seemed to connect faintly at this moment, yet still hadn't formed a chain of evidence to pinpoint a suspect. The question marks in the investigation log remained prominent, as if waiting for more details to fill in the answers.
By the time Xiao Yang and Xiao Sun made some progress, the body had already been transported back to the Criminal Investigation Detachment.
The stainless steel table in the autopsy room gleamed coldly under the operating lights. When Zhang Jianguo's body was brought in, the body bag was still stained with warehouse engine oil. Zhang Lin, wearing double-layered rubber gloves, released a strange odor—a mixture of engine oil and putrid gas—the moment his fingertips gripped the zipper of the body bag. "First, do a 3D scan of the body surface," he said to his assistant, Xiao Lin, without looking up. The scanner's laser beam swept across the body's surface. "Pay close attention to the laceration on the left forehead, especially the width of the laceration at the wound edge, and compare it with the steel pipe found at the scene."
Xiaolin adjusted the scanner parameters, and the point cloud model on the screen gradually outlined the contours of the corpse. "Teacher Zhang, the deceased has a 3.5x4cm laceration on the left forehead," she said, placing a ruler at the edge of the wound. "The wound angle is blunt and rounded, accompanied by a 3mm wide contusion band. There are interstitial bridges within the wound cavity, consistent with the characteristics of blunt force trauma." Zhang Lin leaned closer to examine it, gently pressing his fingers against the skin around the wound. The decaying subcutaneous tissue trembled slightly under his fingers: "Measure the depth of the wound: 2.8cm, reaching the outer table of the skull. This level of injury is enough to cause impaired consciousness, but not fatal."
The body temperature was measured deep in the rectum. When the electronic thermometer reading stabilized at 23°C, Zhang Lin drew a horizontal line on the autopsy record. "Ambient temperature 25°C, core body temperature 23°C, temperature difference 2°C," he said, referring to the Henssge body temperature equation table. "Based on the normal rate of body temperature decline, the time of death should be 48-60 hours, but the humidity in the warehouse is high, requiring a correction factor of 0.9." Xiao Lin suddenly pointed to the body's elbow joint: "Rigoletto has progressed throughout the body, the temporomandibular joint is stiff, and the wrist joint range of motion is less than 1 cm. This is characteristic of death 24-36 hours under normal temperature, but high humidity will delay the relief of rigor mortis."
“Based on a comprehensive assessment,” Zhang Lin said, his scalpel making a precise Y-shaped incision on the corpse's chest. Subcutaneous fat rolled outwards beneath the blade, resembling a block of frozen butter. “The time of death should be between 10 PM on July 14th and 2 AM on July 15th, six hours later than estimated based solely on body temperature. This is because the warehouse's 62% humidity is equivalent to a naturally occurring high-humidity environment, slowing the decomposition process by 15%.” He instructed Xiao Lin to extract muscle tissue samples for “creatine kinase activity testing. This enzyme's activity decreases linearly with time of death, accurate to the hour.”
When the chest cavity was opened, the putrefied lung tissue was grayish-red, like a bloated sponge. Zhang Lin used scissors to separate the bronchi, and mucus was drawn into thin strands on the blades. "The lungs weigh 1450 grams, 200 grams heavier than normal," he pointed to the hemorrhage points under the pleura.