The crackdown on organized crime began with the arrest of the mother-in-law.

Chapter 1365 Comprehensive Judgment and Analysis of the Cause of Death

"We can't jump to conclusions; drowning requires a comprehensive assessment of multiple indicators." Zhang Lin sliced ​​the lungs and placed them in a beaker of water. "You see, the lung tissue floats on the surface because the alveoli are filled with air and liquid, reducing their density. But we also need to check the respiratory and digestive tracts for drowning components, as well as the diatom content in the blood." He then cut open the trachea and bronchi. "A small amount of pale green liquid was found in the trachea, containing reed fibers and algae fragments, consistent with the substances found in the water environment at the scene. This is crucial evidence of drowning."

During the heart examination, Zhang Lin discovered abnormalities: "The heart was of normal volume, weighing 350 grams, with no bleeding points under the epicardium, but the left ventricular myocardium was pale in color, and the blood in the heart chambers was dark red and poorly coagulated, consistent with myocardial damage caused by hypoxia." He extracted a blood sample, "sending it for diatom testing and blood gas analysis, while also testing the blood for alcohol content and toxins to rule out the possibility of death by poisoning."

The abdominal dissection proceeded methodically. "There was no blood or fluid accumulation in the abdominal cavity. The liver, spleen, kidneys, and other solid organs were of normal size and uniform color, with no ruptures or infarcts. The stomach contents were approximately 150 grams, in a semi-digested state, containing rice, vegetables, and a small amount of meat residue. The gastric mucosa was smooth, without bleeding or ulcers." Based on the degree of digestion of the stomach contents, Zhang Lin determined, "The gastric emptying rate was approximately 50%. Considering the types of food, we estimate the last meal was 4-6 hours before death."

“张老师，这对推断死亡时间很有帮助。”小林立即记录，“死者7月10日晚上9点半从刘长根家离开，假设他在离开前吃过晚饭，那死亡时间可能在7月10日晚上11点半至7月11日凌晨1点半之间？”

"This is just a preliminary estimate. Determining the time of death requires a comprehensive judgment based on multiple indicators, including body temperature, rigor mortis, livor mortis, and the degree of digestion of stomach contents. Especially for bodies in water, the rate of temperature drop differs from that in air, requiring correction." Zhang Lin took out a rectal thermometer and inserted it into the body's rectum. "The rectal temperature is 30.2°C. The water temperature at the scene is 26°C. According to the formula for the temperature drop of bodies in water, it takes about 1.5-2 hours for the rectal temperature to drop by 1°C. The normal human rectal temperature is 37°C. Based on this calculation, the time of death is about 3.4-4.5 hours? No, there's a problem here."

Zhang Lin frowned: "The temperature drop of a body in water is affected by many factors, including water flow speed, water temperature, and the degree of obesity in the body, so a simple formula cannot be applied. The deceased was of medium build, with 1.5 cm of subcutaneous fat, which is within the normal range. Moreover, the water at the scene was still, with a slow current, so the temperature drop should be slower than in flowing water. We need to adjust this based on the development of rigor mortis and livor mortis." He recalled the data from the external examination of the body: "Rigoletto had spread throughout the body, reaching intensity level 3. Rigor mortis usually reaches full-body rigidity 12-16 hours after death; livor mortis was pale purplish-red, did not completely fade upon pressure, and new livor mortis formed slowly after changing the body position, which is consistent with the characteristics of livor mortis 6-12 hours after death."

"Based on all these indicators, in which range should the time of death fall?" Kobayashi pressed.

“胃内容物消化程度提示末次进食后4-6小时死亡，尸僵和尸斑提示死后6-12小时，尸温结合水域环境校正后，提示死后8-10小时。”张林将所有数据汇总分析，“取中间值，同时考虑到水中尸体腐败速度较慢，将死亡时间推断为7月10日晚上10点至7月11日凌晨1点之间，最可能的死亡时间是7月10日晚上11点左右。”

The autopsy continued until 5:00 AM, and all organ samples and physical evidence were collected and sent to the laboratory for further testing. At 9:00 AM, the results of the various autopsy examinations were successively reported back: "Teacher Zhang, the blood diatom test result is positive, detecting diatoms of the class Pterygota, consistent with those found in the Qingling Lake waters, with a content of 2300 per 100 grams of tissue, exceeding the diagnostic threshold for drowning (1000 per 100 grams of tissue); blood gas analysis shows a blood pH of 7.21, a carbon dioxide partial pressure of 65 mmHg, and an oxygen partial pressure of 32 mmHg, consistent with respiratory acidosis caused by drowning; blood alcohol content is 0.02 mg/100 ml, which does not meet the standard for intoxication, and no common toxic components were detected."

"The histopathological examination results for the subcutaneous hemorrhage area in the neck are also in." Xiaolin held the pathology report. "Under the microscope, ruptured capillaries and extravasation of red blood cells were observed in the subcutaneous tissue, accompanied by a small amount of neutrophil infiltration, which is consistent with the ante-mortem injury. The time of injury is consistent with the time of death."

Zhang Lin finally breathed a sigh of relief. All the evidence had come together: "The cause of death was mechanical asphyxiation combined with drowning. The process of injury should be: the perpetrator first used a soft object (such as a rope or scarf) to compress the left side of the victim's neck, causing subcutaneous bleeding and temporary asphyxiation, rendering the victim unable to resist. The perpetrator then pushed the victim into the water, leading to the victim's eventual drowning. The subcutaneous bleeding in the neck was a pre-mortem injury, while indicators such as emphysema, respiratory fluid composition, and positive cardiac blood diatoms confirmed that drowning was the final cause of death."

"Then why are there no nail marks or rope marks on the neck indicating strangulation?" Kobayashi still had a question.

"It's possible that the weapon used to inflict the injury was unusual, such as a wide scarf or towel. These types of tools exert pressure over a large area, leaving less noticeable marks. Furthermore, the prolonged immersion of the body further blurred the marks. However, subcutaneous bleeding will not disappear, which is the strongest evidence," Zhang Lin explained. "Moreover, the fiber sample from the nail fold of the deceased's right index finger, after testing, matched the black fiber composition extracted from the scene. Combined with the abrasions on the left palm, this indicates that the deceased did indeed fight with the assailant before death, but was ultimately subdued due to the disparity in strength."

At 10:00 AM, Zhang Lin completed the detailed autopsy report and brought it to Li Ming's office. Li Ming was currently frowning at the clue diagrams on the wall; the case had reached a stalemate due to Zhao Yonghong's elimination. Seeing Zhang Lin enter, he immediately stood up: "Forensic Doctor Zhang, what are the autopsy results? Have the cause and time of death been determined?"

"Captain Li, the autopsy report is complete. All data and test results have been verified three times, and the conclusion is accurate." Zhang Lin placed the autopsy report on the table and opened to the first page. "The deceased was Zhang Jianguo, male, 47 years old. The cause of death was determined to be mechanical asphyxiation combined with drowning. Specifically, the perpetrator first used external force to compress the neck, causing the deceased to briefly suffocate and lose the ability to resist, and then threw him into the reed marshes of Qingling Lake, ultimately leading to his drowning."

Li Ming's gaze fell on the words "mechanical asphyxiation combined with drowning," and his brows furrowed: "So, it wasn't just simple drowning, but homicide?"