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

The two returned to their office, took out their notebooks, and meticulously compared the newly discovered clues with their previous investigation findings. Wrench fragments, red brick debris, and a nylon safety rope pointed to the construction industry; a size 43 shoe print, a cigarette butt, and brown fibers outlined the suspect's basic characteristics; canvas fragments and metal buttons were related to the victim's belongings. Although these clues hadn't yet formed a complete chain of evidence, each detail was like a piece of a puzzle, and one day it would piece together the whole case.

It was late at night, but the office lights were still on. Yang Lin and Yang Sen were still repeatedly studying the investigation route map, marking the location of every trace they found, hoping that the technical department's test results tomorrow would bring a new breakthrough, allowing the truth to be revealed as soon as possible in this mysterious case of a decomposed corpse in a drainage ditch.

Next, an autopsy will be performed on the body.

At 8 p.m., the temperature control system in the Criminal Investigation Detachment's autopsy room remained stable at 16°C, and the air was filled with a complex odor of disinfectant mixed with the putrid smell. A refrigerated truck carrying a body from a drainage ditch slowly drove into the autopsy corridor. Two staff members, wearing heavy biosafety suits, carefully lifted the dark canvas bag containing the body onto the autopsy table. The surface of the bag was still covered with dark green algae and blackish-brown silt, and the nylon rope at the bag's opening had loosened slightly during transport, vaguely revealing the swollen and deformed outline of the body inside.

"Prepare the dissection instruments. First, conduct a surface examination of the body, focusing on recording the degree of decomposition, surface injuries, binding marks, and any remaining clothing and debris, especially the fibers and silt on the cloth bag. Make sure these match the samples from the scene investigation." Zhang Kai, wearing double-layered latex gloves, spoke through his gas mask, his voice calm and undeniably professional. His assistant, Xiao Lin, had already arranged the dissection trays in order. Scalpels, forceps, thermometers, and other instruments gleamed coldly under the operating lights. Specimen bottles beside them contained saline solution and preservatives, ready to collect various samples at any time.

Xiaolin carefully cut open the canvas bag with scissors, gradually revealing the full body. The body was in a state of moderate decomposition; the skin was white and wrinkled from prolonged immersion in the ditch water, exhibiting typical "washing woman's hands" characteristics. Some skin had separated from the muscle tissue, threatening to fall off with the slightest touch. "The deceased is male, initially estimated to be between 40 and 50 years old, 178cm tall, calculated based on femur length measurements, with an error margin of no more than 1cm." Xiaolin measured various parts of the body with a soft ruler while quickly writing on the record board. "The rigor mortis has completely subsided, and the joints are relaxed, indicating that the time of death has exceeded 72 hours; the livor mortis is dark purplish-red, distributed on the back, buttocks, and unpressed areas of the limbs, and does not fade when pressed, consistent with the characteristics of livor mortis fixed more than 24 hours after death, but due to immersion in the ditch water, the color of the livor mortis is slightly lighter than that of a normally decomposed body, and the edges are more blurred."

Zhang Kai squatted beside the autopsy table, gently puncturing the putrefactive bubbles in the corpse's abdomen with a dissecting needle. Brownish, putrefactive liquid slowly flowed out, carrying a pungent odor of hydrogen sulfide. "Immediately take samples to test the gaseous components of the putrefactive liquid, paying particular attention to the concentration ratio of hydrogen sulfide and ammonia," he instructed Xiao Lin. He then used tweezers to pick up a piece of sloughed skin tissue and carefully examined it under the operating light. "The skin is grayish-white, indicating that putrefaction has entered an active phase. However, the canal water temperature is low, which slows down the putrefaction process more than normal temperature. Look, the putrefactive veins in the chest and abdomen are distributed in a tree-like pattern, a typical sign of 4-6 days after death. Also, the greenish tinge in the lower right abdomen has spread to the waist. Based on the correlation between the rate of greenish tinge diffusion and water temperature, combined with the recent average water temperature in the drainage canal, we preliminarily judge that the putrefaction process has lasted for 5-7 days."

"How exactly do we determine the effect of water temperature on the time of death? We've mostly dealt with terrestrial decomposing bodies before, and we don't have much experience with underwater bodies," Xiaolin asked, pausing his pen. Zhang Kai took out his copy of "Atlas of Forensic Pathology" and turned to the "Table of Decomposition Process of Underwater Bodies": "The water temperature in the drainage ditch is 5-6°C lower than normal temperature, which slows down the decomposition rate by about 20%-25%. For example, a terrestrial body will enter severe decomposition in 5 days, while an underwater body will take 7-8 days. However, this body's decomposition level is between moderate and severe, indicating that the time of death is slightly shorter than calculated solely based on water temperature. It's possible that the body stayed on land for a period of time after death before being thrown into the ditch—this needs further verification by combining stomach contents and surface injuries."

During the subsequent examination of the body's external injuries, Zhang Kai made a crucial discovery. Shining a powerful searchlight 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 detached skin tissue. "There's a band-like indentation about 0.8 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 residue is visible 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 canal water?" Xiao Lin asked, peering closer. 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 canvas 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 2×3cm wound on the right temporal region of the body, with obvious contusions at the edges. A small amount of silt and brick fragments were visible inside the wound cavity, and 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 2.5cm 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 discovered an anomaly on the corpse's right palm: multiple irregular abrasions on the skin, and small amounts of red brick fragments and brown fibers embedded in the fingernails. "Should these fragments and fibers be sent for testing immediately?" (End of Chapter)