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

For example, a body on land will enter severe decomposition within 5 days, while a body in water requires 7-8 days. However, this body's decomposition level is between moderate and severe, indicating that the time of death was slightly shorter than estimated based solely on water temperature. It's possible that the body remained on land for a period after death before being thrown into the water. This requires further verification by examining the stomach contents and surface injuries.

During the subsequent examination of the body's external injuries, Zhang Kai made a crucial discovery. Shining a powerful forensic lamp on the neck, he could vaguely see a light brown band-like mark encircling the neck in the folds of the decomposing skin. "There's something unusual here," Zhang Kai said, gently parting the skin folds with tweezers, carefully avoiding any loose skin tissue. "There's a band-like indentation about 1 cm wide running from the left to the right side of the neck. The edges of the indentation are irregular, and there's slight damage to the skin in the area. A small amount of fiber remains at the damaged area. Although prolonged soaking has softened the fibers, they can still be identified as cotton or linen."

"Could it be marks left by friction from a canvas bag, or from debris entangled in the water?" Xiao Lin asked, getting closer to examine the marks. Zhang Kai shook his head and took out a ruler to measure the marks: "The marks are of uniform depth and form a complete closed loop around the neck, which doesn't match the irregular shape of the marks from the bag friction, nor the loose marks from debris entangled in the water. In addition, the neck muscle tissue corresponding to the marks shows a small amount of residual bleeding under the dissecting microscope. Although soaking caused the blood to dissolve, the dark red staining between the muscle fibers still proves that this was an injury sustained before death. The preliminary judgment is that it was a strangulation injury caused by strangulation with a strap."

On the head of the deceased, Zhang Kai also discovered a significant injury. There was an irregular 3×4cm wound on the left temporal region, with obvious contusions at the edges. A small amount of mud, sand, and debris from aquatic plants were visible within the wound cavity. A slight indentation could be felt on the surface of the skull upon palpation. "The wound's irregular shape and missing tissue at the edges are consistent with blunt force trauma," Zhang Kai carefully probed the depth of the wound cavity with a probe. "It's about 3cm deep, and didn't penetrate the inner table of the skull, indicating a moderate impact. Although it didn't cause a skull fracture, it may have caused the deceased to lose consciousness briefly, creating conditions for subsequent strangulation. However, there was no obvious bleeding at the wound. Considering the immersion in water and the degree of decomposition, this injury is likely a non-fatal injury suffered before death, or it may have occurred near the time of death. A head autopsy is needed to confirm this."

Xiao Lin noticed something unusual on the body's right palm: several irregular abrasions on the skin, and small amounts of brown fibers and gray mud embedded in the fingernails. "Should we send these fibers and mud for testing immediately?" Xiao Lin asked. Zhang Kai nodded: "The fiber samples need to be compared with the fibers from the canvas bag found at the scene and the fibers extracted from the reeds. The mud samples need to be analyzed to see if they match the composition of the mud and sand along the North River bank, especially whether they contain volcanic rock particles characteristic of the upstream area. These could be traces left from a struggle between the deceased and the suspect, or from being dragged, and could also help determine if the body disposal site was the primary crime scene."

To confirm the cause of death and obtain more details, Zhang Kai began an autopsy. He used a scalpel to cut along the midline of the abdomen, separating the skin, subcutaneous tissue, and muscle in sequence. Putrefactive gases mixed with the fishy smell of river water rushed out instantly, and Xiao Lin quickly adjusted the exhaust system to minimize the odor. "There was a large amount of pale yellow liquid in the abdominal cavity, about 800 ml, which was initially determined to be a mixture of ascites and river water," Zhang Kai said, using a suction device to remove the liquid. "The liver and spleen were in a semi-liquefied state, soft in texture, and crumbled easily when touched with tweezers, consistent with the putrefaction of tissues 5-7 days after death; the contents of the intestines had been mostly emptied, with only a small amount of brownish pasty material remaining. No undigested food residue was found, indicating that the deceased had eaten 8-12 hours before death. Based on the time of death, the last meal was estimated to have been between 6 pm and 8 pm five days ago."

During the thoracic dissection, Zhang Kai was even more cautious. As the sternum was sawed open, the internal condition of the thoracic cavity gradually became clear. There was obvious collapse in the upper lobe of the left lung, and the lung tissue was dark red. After cutting it open, a large amount of foamy liquid could be seen flowing out. These are typical characteristics of drowning death. However, Zhang Kai frowned: "No, although there are signs of drowning, the weight of the lung tissue is lighter than that of a normal drowned body, and the amount of mud and sand in the alveolar cavity is very small. It is more like a small amount of river water inhaled when the body was thrown into the water after death, rather than suffocation caused by voluntary drowning."

He further examined the neck tissue and found obvious bleeding marks in the neck muscles, sternocleidomastoid muscle, and infrahyoid muscle group. The greater horn of the hyoid bone was fractured, and there was only a small amount of mucus in the trachea and bronchi, with no obvious mud or weeds. This was completely consistent with the previous conclusion of "strangulation." "The cause of death has been determined to be mechanical asphyxiation, caused by strangulation with a strip of material," Zhang Kai said, using tweezers to pick up the damaged muscle tissue in the neck and showing it to Xiao Lin. "The degree of bleeding in the neck muscles and the fracture of the hyoid bone prove that the strangulation force was sufficient to cause death by respiratory failure; while the drowning-like appearance in the lung tissue was caused by river water passively entering the respiratory tract when the body was thrown into the water after death. This is a post-mortem phenomenon and not a true drowning death."

Xiao Lin suddenly realized: "So, the deceased was strangled first and then thrown into the Beihe River? Does that provide evidence for our previous speculation that the body 'stayed on land for a period of time after death'?" Zhang Kai nodded: "That's right. Judging from the vital signs of the neck injury, such as bleeding and muscle contraction, the strangulation occurred before death. The mild drowning characteristics in the lung tissue indicate that the body remained in the water for 1-2 days less than the time of death. In other words, the deceased was thrown into the Beihe River 1-2 days after death. This also explains why the decomposition process is slightly different from that of a body in water alone. In the early stages, decomposition had already begun in the normal temperature environment on land, and the speed slowed down after entering the water."

During the autopsy, Zhang Kai discovered a crucial detail. A small metal fragment was embedded in the skin tissue of the victim's left wrist. The fragment had obvious polishing marks on its edges, and the material was initially identified as brass. "This fragment looks different from the metal hook found at the scene, but its shape resembles a part of some tool," Zhang Kai carefully removed the fragment with tweezers and placed it in a specimen bottle. "We'll send it for analysis of its composition and morphology to see if it came from a wrench, pliers, or other repair tool. This could be an item the deceased carried with them, torn off during the struggle with the suspect, and the fragment embedded in the skin. It could also provide clues to confirm the deceased's identity or occupation."

As the autopsy neared its end, Zhang Kai compiled all the findings, meticulously reviewing each item on the record board. (End of Chapter)