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

Zhang Kai sighed: "Yes, the deceased had no identification items on him, was dressed plainly with no obvious features, and had moderate wear on his teeth, which is consistent with the characteristics of a male aged 45 to 55. However, we cannot deduce his specific identity from his teeth. We have extracted the deceased's fingerprints and DNA samples and sent them to the fingerprint database and DNA database for comparison, but there is no matching information yet."

At 5 PM, Zhang Kai and Xiao Lin completed all the autopsy work and drafted a detailed first draft of the autopsy report. They then went to Lu Chuan's office to report. At that moment, Lu Chuan was reviewing the investigation team's interview records. Seeing Zhang Kai enter, he immediately put down the documents in his hand: "Zhang Kai, have the autopsy results come out? Have the time and cause of death been determined?"

Zhang Kai placed the draft of the autopsy report in front of Lu Chuan, sat down, and began to report in detail: "Captain Lu, after a comprehensive physical examination and autopsy, we have now clarified the basic information and death-related details of the deceased. First, the basic characteristics of the deceased: male, aged 45 to 55, height 175 cm, weight 62.5 kg, black and white hair without any trace of hair dye, no obvious physical characteristics, and his identity has not yet been determined."

"Regarding the cause of death, a detailed examination of all organs ruled out the following possibilities: First, drowning was ruled out, as no drowning components were detected in the lung tissue sample, and there were no obvious drowning-related changes in the lungs; second, fatal trauma was ruled out, as there were no obvious fatal injuries throughout the body, no fractures in the skull, ribs, spine, or other bones, and no ruptures or bleeding in the internal organs; third, poisoning by common toxins was ruled out, as no common toxic substances such as organophosphorus pesticides, sleeping pills, rodenticides, or heavy metals were detected in the stomach contents, liver, and kidney samples; fourth, pathological causes such as digestive tract diseases and cardiovascular diseases were ruled out, as there were no fatal lesions in any of the internal organs."

"The final determined cause of death was mechanical asphyxiation. The main evidence is as follows: First, the deceased's conjunctiva was congested and the cornea was slightly cloudy, which are consistent with the physical characteristics of mechanical asphyxiation; Second, both lungs were dark red, with dilated and congested capillaries in the alveolar walls, and a small amount of dark red blood was oozing from the cut surface, which is consistent with the lung changes of asphyxiation; Third, there was a slight tear in the intima of the deceased's left carotid artery, which is a typical injury caused by neck compression. Although there were no obvious strangulation marks or ligature marks on the neck skin and muscles, it is speculated that the neck was strangled with a soft object, or that the pressure was moderate but lasted for a long time. In this case, no obvious marks may be left on the skin surface; Fourth, the fiber sample extracted from the deceased's fingernails was consistent with the composition of the green fiber sample extracted at the scene, which is speculated to be a remnant from the struggle with the suspect or during the transport process."

Lu Chuan listened attentively, nodding occasionally, and interjected, asking, "Can you determine the specific method of mechanical asphyxiation? Was it strangulation, ligation, or something else?" Zhang Kai replied, "Currently, we lean towards strangulation because no cord-like ligature marks were found on the neck, nor was any related strangulation tool found. However, since there are no obvious strangulation marks on the neck skin, we cannot rule out the possibility of using a soft object to assist in strangulation. Further investigation is needed, combining fiber samples and trace evidence collected at the scene, to further confirm the murder weapon."

"What is the result of the estimated time of death? This is crucial to the case investigation," Lu Chuan continued to ask. Zhang Kai presented relevant data recorded during the autopsy and explained in detail: "Based on a comprehensive analysis of multiple pieces of evidence, we deduced that the time of death was between 11 PM the night before last and 2 AM yesterday. There are three specific bases for this: First, the state of rigor mortis and livor mortis. Rigor mortis had spread to all the major joints, and the livor mortis did not fade upon pressure, remaining a dark purplish-red color, consistent with the characteristics of death 24 to 36 hours prior. Second, the degree of digestion of the stomach contents. There were small amounts of undigested rice, vegetables, and meat in the stomach, suggesting the last meal was 4 to 6 hours before death. Assuming the last meal was between 7 and 8 PM the night before last, then the time of death would be between 11 PM the night before last and 2 AM yesterday. Third, considering the testimony of the person who reported the incident, who did not find the body when cleaning the drainage ditch at 9 AM yesterday, it indicates the body was dumped into the ditch between 9 AM yesterday and 9 AM this morning. Since the time of death should have been before the body was dumped, we further determined the time of death to be between 11 PM the night before last and 2 AM yesterday, and the time of dumping to be between last night and this morning."

"What other valuable clues were found during the autopsy?" Lu Chuan asked. Zhang Kai replied, "The following are some important findings: First, there was a superficial scratch on the back of the deceased's right hand with irregular edges. Skin tissue and secretions from the scratch were extracted, and further testing can determine whether it was caused by a struggle. Second, soil samples consistent with the composition of silt from the drainage ditch at the scene were extracted from under the deceased's fingernails, as well as fiber samples consistent with the composition of green fiber samples from the scene, indicating that the deceased had contact with the scene environment or the murder weapon before or after death. Third, the sole pattern of the deceased's black cloth shoes was clear, and pattern samples have been extracted for comparison with footprints extracted from the scene. Fourth, fingerprints and DNA samples of the deceased were extracted and sent to the database for comparison, but no matching results have been found yet. Fifth, 24 samples were extracted during the autopsy, including liver, kidney, lung, brain tissue, and stomach contents, all of which have been sent to the technical department for further pathological examination and toxicology review to ensure that no poisoning or pathological factors were missed."

"What are the current difficulties?" Lu Chuan asked, his brow furrowed slightly. Zhang Kai sighed, "There are two main difficulties: First, the identity of the deceased cannot be determined. There were no identification items on the deceased's body, the clothing was ordinary and unremarkable, and there are no results from fingerprint and DNA database comparisons, which has brought considerable difficulties to the case investigation; second, it is impossible to directly identify the suspect. No direct traces of the suspect were found on the deceased during the autopsy, such as hair, fingerprints, or DNA, and the murder weapon has not yet been identified. We need to combine the trace evidence collected at the scene with the results of subsequent interviews and investigations to further narrow down the suspect pool."

"Based on the autopsy results, what are your initial analyses and judgments about the case?" Lu Chuan asked. Zhang Kai thought for a moment and then said, "Combining the autopsy results and the scene, I have the following preliminary judgments:"
First, the suspect had a certain level of counter-surveillance awareness, choosing to dispose of the body in a drainage ditch in an old community where surveillance was blind, and may have used a soft object to assist in strangulation, leaving no obvious traces on the victim's body.

Secondly, the suspect may have known the deceased or had a good understanding of the deceased's living habits and activity patterns; otherwise, it would be difficult to accurately grasp the deceased's travel time and commit the crime.
Third, the vehicle used to dispose of the body may have been an electric tricycle or a small truck, which is consistent with the tire tracks found at the scene. The suspect may have used a vehicle to transport the body to a drainage ditch for disposal.
Fourth, the deceased's last meal occurred 4 to 6 hours before death, suggesting that the victim was subdued and murdered shortly after eating. The crime scene was likely the victim's home or a place familiar to the victim, after which the body was disposed of in a drainage ditch in the Jianshe Road community. (End of Chapter)