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

"The wound edges are irregular, with epidermal peeling. The muscle tissue in the center of the defect is dark red. Hemolysis caused by putrefaction has masked some of the vital signs, but the deep sternocleidomastoid muscle shows a tendency to bleed." Xiaolin suddenly raised his camera, the shutter sound particularly clear in the silence: "Do we need to do a tissue section?" "First, extract muscle fiber samples for frozen sections," Zhang Kai's scalpel precisely avoided blood vessels, "to see if there is any contraction band formation, which is an important sign of antemortem injury."

When the chest cavity was opened, the putrefied lung tissue, like a bloated sponge, crumbled at the slightest touch in the tray. "The lungs weighed 1900 grams, 1.8 times the normal weight," Zhang Kai said, separating the bronchi with scissors. "There was a large amount of putrefied debris inside the bronchial lumen, but the submucosal hemorrhages were pinpoint-sized and distributed along the bronchial tree, which was not caused by putrefaction." He asked Xiao Lin to take samples, "to test for diatoms to rule out drowning, but to focus on checking for foreign body aspiration." The assistant used forceps to pick up a piece of lung tissue and let it float in formalin solution: "There were also crescent-shaped hemorrhages under the pleura, consistent with death by asphyxiation."

The extraction of stomach contents was carried out with the hum of a negative pressure suction device, and pale green chyme mixed with putrefactive gases surged out. "About 600 ml, containing undigested rice grains and meat fibers," Zhang Kai examined the sample under a microscope. "The transverse striations of the meat fibers are still clear, indicating death occurred 4-6 hours after ingestion." Xiao Lin suddenly pointed to the stomach lining: "There's a 0.5 cm ulcer here, with bleeding at the edges. Could it be related to the cause of death?" Zhang Kai shook his head, and with a scalpel, he cut open the entire thickness of the stomach wall: "The base of the ulcer is fibrotic, indicating an old lesion. There's no acute inflammatory reaction around it, ruling out its lethality."

There was a 4×5cm subcutaneous hematoma on the right temporal region of the corpse. When Zhang Kai lifted the scalp, the decomposed periosteum separated from the bone plate. "The skull X-ray shows a linear fracture of the right temporal bone, about 6cm long," he probed along the fracture line. "The fracture line extends to the base of the skull, accompanied by suture separation. This injury is sufficient to cause intracranial hemorrhage." The moment the cranial cavity was opened, the decomposed brain tissue was grayish-red, like melted tofu. "A thin layer of hematoma, about 30ml in volume, was visible under the dura mater. The subarachnoid hemorrhage was most pronounced in the longitudinal fissure of the brain, consistent with traumatic brain injury caused by blunt force trauma."

“Teacher Zhang, look at the deceased’s hands,” Xiao Lin suddenly lifted the corpse’s wrists, the grime under the fingernails gleaming metallically under the operating light. “X-ray fluorescence analysis shows the presence of elements such as iron and zinc, consistent with the composition of rust in the parking lot.” Zhang Kai wiped the fingernails with a sterile cotton swab. “We’ll extract biological samples for DNA typing; there might be skin tissue from the murderer.” He noticed an old fracture in the deceased’s right ring finger, with good callus formation. “This fracture has healed for over two years; it needs to be highlighted when comparing it to the missing persons database.”

The corpse had extensive abrasions and contusions on its back. When Zhang Kai turned the body over, putrefactive fluid pooled in a thin stream in the groove of the autopsy table. "The contusions are distributed in patches, covering an area of ​​about 20×15cm," he measured the boundaries of the contusions. "The vital signs have been disrupted by putrefaction, but the bleeding bands in the deep muscles are still clearly visible, consistent with the characteristics of being dragged before death, and matching the drag marks in the parking lot." Xiao Lin took a sample from the center of the contusions. "The myoglobin content of the muscle tissue was 230ng/mL, higher than the normal level, indicating muscle contusions caused by ante-mortem injury."

The extracted blood formed a dark red clot in the vacuum blood collection tube. As Zhang Kai injected the sample into the blood gas analyzer, the values ​​on the screen gradually appeared. "Blood oxygen saturation 42%, carbon dioxide partial pressure 78 mmHg," he reported the data. Xiao Lin's pen highlighted the key points in the record, "Consistent with death from hypoxia, but not typical asphyxiation; more like respiratory center depression caused by traumatic brain injury." He instructed Xiao Lin to perform toxicological analysis, "Focus on barbiturates and organophosphates to rule out poisoning."

When dissecting the abdomen, Zhang Kai's scalpel traced precise arcs along the mesentery of the small intestine. Forceps gently lifted the translucent membrane, revealing scattered hemorrhages like red beans sprinkled on a green cloth. "The distribution of these hemorrhages is very interesting," he said, adjusting the angle of the operating light so the beam shone through the mesentery, revealing the branches of capillaries. "They are 0.2-0.5 cm in diameter, with blurred edges, and haven't merged into patches—typical changes in nonspecific sudden death." He had Xiao Lin measure the largest hemorrhage with calipers. "But considering the fracture in the right temporal lobe and the subdural hematoma, the primary cause is microcirculatory disturbance due to traumatic shock. These hemorrhages are peripheral manifestations of the compensatory phase of shock."

As the gallbladder was gently pulled out with dissecting forceps, dark green bile swayed within the transparent bladder wall, like a piece of solidified jade. "The gallbladder has a volume of about 60ml and is 80% full," Zhang Kai said, drawing 5ml of bile with a syringe. The liquid in the syringe gleamed with a metallic sheen. "The bilirubin concentration is 12mg/dL, which is 3mg/dL higher than the average value 48 hours after death." He had Xiao Lin drop a drop onto the colorimetric card, and the value corresponding to the dark green color on the standard card matched the instrument's measurement perfectly. "The degree of bile concentration is positively correlated with the degree of rigor mortis relief. Look at the deceased's jaw joint," he gently moved the body's jaw, "it can easily open 4cm. The rigor mortis in the wrist joint has completely subsided, while the ankle joint still has slight ankylosis. This uneven state of relief is consistent with the characteristics of 4-5 days after death."

Xiaolin suddenly drew a line on the autopsy record, emphasizing the words "ambient temperature": "Teacher Zhang, the nighttime temperature in the parking lot these past few days has only been 18℃, and the daytime high is only 25℃, which is 3-4℃ lower than the same period in previous years." She pulled up the weather data on her phone; the temperature curve on the screen resembled a gentle wave. "Low temperatures significantly slow down the decomposition process, especially the reproduction rate of intestinal flora. Based on this temperature, could the actual time of death be longer than what the post-mortem phenomena suggest?"

Zhang Kai put down his scalpel and walked to the corpse's feet, gently pressing the skin on the calf. The pressure mark took two seconds to fully heal. "Look at the skin's elasticity," he gestured for Xiao Lin to come and touch it. "The degree of skin laxity caused by decomposition is 20% less than that of a corpse that died five days ago at standard temperature." He flipped open the corpse's eyelids; the putrefied venous network of the bulbar conjunctiva was tree-like and had not yet spread to the corneal margin. "The corneal opacity is grade two, and the pupil can still transmit light to see the lens. This is a characteristic of a corpse that died three days ago at 25°C, but the low temperature of 18°C ​​would delay this process by 12-24 hours."

He asked Xiaolin to fetch a rectal thermometer. After the probe was slowly inserted, it showed a temperature of 21°C at a depth of 10cm. "Ambient temperature 18°C, core body temperature 21°C, temperature difference 3°C," Zhang Kai typed on the calculator. (End of Chapter)