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

After three or four hours of on-site investigation, the situation here was basically clear and the relevant work had come to an end.

The body was transported to the autopsy room of the Criminal Investigation Brigade.

The stainless steel door of the autopsy room closed with a dull sound. Zhang Kai adjusted the angle of the shadowless lamp, and the cold white beam accurately covered the autopsy table. Wang Xuebing's body was blue-gray under the light, and the blood clots on his chest looked like ugly lines. With the removal of the breathing device, the stiffness of his limbs caused by rigor mortis became even more weird.

"At 4.2:1.8 pm, the autopsy of Wang Xuebing's body officially began." Zhang Kai clearly reported the time to the recorder. The breathing sound under the protective mask was amplified by the microphone and echoed in the empty room. He first used a vernier caliper to measure the fatal wound. The caliper of the metal caliper gently clamped the wound on the left chest: "The wound is 45 cm long and cm wide, oval, with a smooth edge and no serrations, which is consistent with the characteristics of a single-edged sharp object piercing from top to bottom at a -degree angle." The moment the tip of the knife opened the skin, dark red tissue fluid oozed out, and he quickly absorbed it with a cotton ball. "There was obvious subcutaneous bleeding around the wound, and the reaction was strong. It was confirmed to be an injury before death."

The scalpel cut along the midline of the body, and the sharp blade made a fine "rustling" sound when cutting the skin. Zhang Kai held the edge of the skin with tweezers in his left hand, and the knife in his right hand accurately separated the subcutaneous fat layer: "The seven knife wounds on the abdomen are irregularly distributed diagonally, the longest is 3.1 cm, and the shortest is 1.9 cm. The depth did not touch the internal organs. It should be a tentative attack." He suddenly stopped and probed into one of the wounds with a probe, "Pay attention to this wound, there are fine fiber residues on the edge, record the number of evidence bag 07."

The process of opening the chest cavity was accompanied by the harsh buzzing of the bone saw, and white bone chips splashed on the protective mask. Zhang Kai carefully removed the sternum, revealing a heart that had beaten countless times: "The left ventricle was penetrated, and the wound was consistent with the position of the wound on the body surface. The aorta ruptured and caused acute massive bleeding." He picked up the broken myocardial tissue with tweezers. "The muscle tissue at the edge of the wound was everted, indicating that the murder weapon was pulled out with a rotational motion." Suddenly, his pupils contracted. "A metal stent was implanted in the coronary artery. The model is XX-2020 and has been implanted for at least two years."

When turning to the abdominal dissection, the stench suddenly became strong as the gastrointestinal tract was exposed. Zhang Kai put on a gas mask and carefully cut the stomach wall with scissors: "The stomach contents are about 250 ml, including salmon, avocado, sushi rice and other ingredients, mixed with wine residue." He poured the contents into the sieve to filter, "The salmon meat remains in block shape, and the digestion degree is about 20%. Combined with the gastric emptying rate calculation," he tapped the calculator on the dissection table, "two to two and a half hours after the meal, which coincides with the time of death." Suddenly, he picked up a ball of white flocs with a glass rod, "I found suspicious powder, and took a sample to send to the toxicology laboratory for inspection."

During the urogenital examination, Zhang Kai cut open the prostate capsule: "The gland volume has increased to 1.8 times the normal size, the gland ducts have dilated, and the interstitial fibrosis is severe." He used a glass slide to scrape tissue samples, "Chronic prostatitis, the course of the disease is at least five years, can cause urination difficulties, sexual dysfunction and other symptoms." When checking the pubic symphysis, his scalpel gently tapped: "There is an old bone fracture on the upper edge of the pubic bone, which took about three years to heal. The X-ray image shows that it was caused by blunt impact."

The final head dissection was full of ritual. Zhang Kai used an electric saw to cut open the skull along the coronal suture. When the complete crown was removed, the sulci on the surface of the brain tissue were clearly visible: "There is no hemorrhage in the subarachnoid space, and no contusion was found in the brain parenchyma, ruling out the possibility of death from craniocerebral trauma." He suddenly noticed a tiny plaque in the temporal lobe, "Take a pathological section, this abnormal area needs further analysis."

The autopsy lasted nearly four hours. When Zhang Kai took off his protective suit, his back was already soaked with sweat. "The cause of death was confirmed to be hemorrhagic shock caused by a sharp injury to the heart." He summarized into the recorder, "The deceased suffered from severe cardiovascular disease and chronic prostatitis. He suffered violence three years ago, which resulted in a sternum fracture and pubic fracture. Benzodiazepine sleeping pills were detected in the stomach. Although they are not enough to cause coma, they will reduce reaction speed and muscle strength." He looked at the body that was re-stitched on the dissection table, "This information can restore the health status of the deceased before his death, but it cannot directly point to the murderer..."

The routine autopsy has been completed, but Zhang Kai is still working on the precise determination of the time of death.

"Test the activity of digestive enzymes in the stomach contents." Zhang Kai suddenly said to his assistant.

After death, the digestion process in the stomach does not stop immediately, and the change in the activity of digestive enzymes can become a "clock" to accurately determine the time of death. The assistant quickly puts the stomach content sample into the centrifuge, and the transparent test tube rotates at high speed in the instrument to separate the clear liquid on the top.

Zhang Kai carefully took out a small amount of liquid and dropped it on the slide. Under the microscope, the active reaction of digestive enzymes was like a tiny battlefield. "Pepsin will continue to break down proteins at body temperature, but as the body temperature drops after death, the activity will also weaken." He muttered to himself while observing, "The degree of protein breakdown of food in Wang Xuebing's stomach is slower than the conventional calculation."

He called up the body temperature curve and slid his fingertips along the broken line on the chart. When the body was found, the rectal temperature was 28°C. According to the normal body cooling rate, the time of death should be around 9 o'clock. But Zhang Kai noticed a detail - the central air conditioner in the deceased's home was set at 18°C, and the low temperature environment slowed down the cooling of the body. "Low temperature not only affects the cooling of the body, but also reduces the activity of digestive enzymes." His eyes suddenly lit up.

In order to verify this speculation, Zhang Kai began to conduct simulation experiments. He placed the same food samples at 18°C ​​and room temperature, and added digestive enzymes extracted from the stomach of the deceased. As time went on, there was a significant difference in the degree of digestion of the two samples. The digestion progress of food at 18°C ​​was nearly half an hour slower than that at room temperature.

At the same time, he conducted a more detailed test on the liver of the deceased. Lactate dehydrogenase (LDH) in the liver will gradually decompose after death, and by detecting changes in its activity, it can also assist in determining the time of death. Zhang Kai ground the liver tissue into a homogenate, and after complex centrifugation and purification steps, he finally obtained a pure enzyme sample. On the precise detector, the numbers kept jumping and finally stopped at a key value.

"Combining the digestive enzyme activity of stomach contents, the corrected value of body temperature, and the LDH activity of the liver," Zhang Kai wrote down the conclusion on the data analysis table, "Wang Xuebing's time of death should be 10 o'clock last night." This judgment, accurate to the hour, was based on countless tests and corrections. (End of this chapter)