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

The police car drove off the grassland road and headed towards the city. The grassland outside the window was gradually enveloped in night, with only the lights of distant herders' homes flickering intermittently. The technical department's testing continued; a race against time was quietly underway in the criminal investigation team's laboratory—everyone was hoping that these small samples would bring a crucial turning point in solving the case.

Meanwhile, the body has been transported back to the Criminal Investigation Division for an autopsy.

At 3 PM, the temperature control system in the Criminal Investigation Detachment's autopsy room remained stable at 16℃, 2℃ lower than the standard autopsy temperature—a parameter Zhang Kai had specifically adjusted to slow down the decomposition of the body. A refrigerated truck carrying the body from the grassland slowly drove into the passageway, and two staff members, wearing biosafety suits, carefully lifted the body onto the autopsy table. The body was wrapped in a sealed bag; even through the transparent bag, one could see the grass clippings and black soil clinging to the dark blue overalls, and the ripped collar of the gray short-sleeved T-shirt was particularly glaring.

"Prepare the dissection instruments. Begin with a surface examination, focusing on recording the characteristics of injuries and the degree of decomposition." Zhang Kai, wearing double-layered latex gloves, spoke through his gas mask with a slight muffled thud. His assistant, Xiao Lin, had already arranged the dissection trays in order; tweezers, scalpels, bone saws, and other instruments gleamed coldly under the operating lights. He opened the sealed bag, and a faint smell of decay filled the air—the body was only slightly decomposed, with pale green livor mortis only in the groin and armpits, consistent with decomposition characteristics within 24-36 hours of death.

"The deceased was male, preliminarily estimated to be 35-45 years old, 178cm tall (based on tibia length), with normal development and moderate nutrition." Xiaolin measured and recorded at the same time. "Rigoletto is distributed throughout the joints of the body. The stiffness of the jaw joint, neck, and limb joints reached level III, with obvious resistance when pressed. Combined with the ambient temperature of 20℃ during the day and 15℃ at night in the grassland, this is consistent with the development pattern of rigor mortis 18-24 hours after death."

Zhang Kai squatted beside the autopsy table, pressing the livor mortis on the corpse's back with his fingers: "The livor mortis is dark purplish-red, located on the back, buttocks, and the back of the limbs where no pressure was applied. The color does not completely fade when pressed, indicating that the livor mortis has entered the diffusion stage after death, and the formation time is about 12-24 hours. Combining the characteristics of rigor mortis and livor mortis, the time of death is initially determined to be between 8 pm on August 15 and 2 am on August 16."

"Should we use body temperature to make a more precise determination?" Xiao Lin took out a rectal thermometer, preparing to insert it into the corpse's anus. Zhang Kai nodded: "We must measure it. Body temperature is one of the most objective indicators for determining the time of death." The thermometer showed a rectal temperature of 23°C. Zhang Kai calculated using the formula for body temperature drop: "The temperature in the autopsy room is 16°C. The body took 2 hours to be transported from the grassland to the detachment. During this time, the body temperature dropped by about 1°C. Extrapolating backwards, the initial body temperature after death is calculated to be 37°C. The temperature drops by 0.8°C per hour, which gives us a time of death of about 22 hours. This is basically consistent with the time range for rigor mortis and livor mortis. The final determination of the time of death is between 10 pm on August 15th and 1 am on August 16th, with an error of no more than 1 hour."

During the subsequent examination of the external injuries, Zhang Kai made a crucial discovery: "There was a 4×1.5cm area of ​​epidermal abrasion with subcutaneous hemorrhage on the left side of the deceased's neck. The bleeding area was dark purplish-red in color, fading at the edges, consistent with the characteristics of injuries caused by blunt force friction before death. It is speculated that the instrument used to injure the victim was rough cloth or rope." He gently lifted the skin at the injury site with a dissecting needle. "There were a few bleeding points in the subcutaneous tissue of the abraded area, and no obvious rupture was observed in the muscle layer, indicating that the intensity of the external force was moderate and did not cause damage to the deep tissues of the neck."

On the deceased's right forehead, Zhang Kai also found a 3×2.5cm subcutaneous hematoma with a 0.5cm epidermal abrasion in the center: "The abrasion has irregular edges and a small amount of mud and sand residue, consistent with ante-mortem injury caused by a blunt object. The weapon used may have been a stone or a wooden stick." He asked Xiao Lin to collect mud and sand samples from the abrasion site, "to compare them with the black soil composition of the grassland slope to confirm whether the injury was caused at the scene."

The most critical injury was found in the victim's chest: "There was a 2×0.8cm stab wound in the 4th-5th intercostal space on the left side of the sternum. The stab wound was spindle-shaped with neat edges and one blunt and one sharp corner. The depth was 6cm." Zhang Kai inserted a probe into the stab wound to investigate. "The probe could touch the surface of the heart, indicating that the stab wound had penetrated the chest wall and may have damaged the heart or major blood vessels. This was very likely the fatal injury."

To determine the cause of death, Zhang Kai began an autopsy. He used a scalpel to make an incision along the midline of the abdomen, separating the skin, subcutaneous tissue, and muscles in sequence to expose the thoracic and abdominal cavities. "There was a small amount of blood in the thoracic cavity, about 100ml," Zhang Kai said, using a suction device to remove the blood. "There was a 1.5×0.6cm puncture wound on the anterior wall of the left ventricle, which penetrated the ventricular wall and reached the right ventricle. There were a large number of blood clots in the ventricular cavity, which are typical characteristics of death from hemorrhagic shock caused by cardiac puncture."

Xiaolin observed the heart tissue section under the microscope: "The myocardial fibers were clearly broken, and a large number of red blood cells were spilled around the wound, accompanied by an inflammatory reaction, confirming that it was a puncture wound before death, ruling out the possibility of post-mortem injury. In addition, a small amount of black fibers were found in the tissue section of the subcutaneous hemorrhage area of ​​the neck, which is consistent with the fiber composition of the black cloth held in the right hand of the deceased, indicating that the neck injury is related to friction with the cloth."

"What about the neck injury and head hematoma? Were they caused by fighting with the suspect before death?" Xiaolin asked doubtfully. Zhang Kai nodded: "Most likely. The skin peeling off the deceased's neck was probably caused by friction when the suspect covered his mouth and nose with cloth; the head hematoma was probably caused by being hit with a stone by the suspect during the struggle. But these are not fatal injuries. The real cause of death is hemorrhagic shock caused by a stab wound to the heart. A stab wound is a fatal injury, and the weapon used to inflict the injury was quite sharp, possibly a dagger or a sharp knife."

During the autopsy, Zhang Kai also discovered some details: "The deceased's stomach contents were approximately 50ml, consisting of partially digested rice, meat, and vegetables. The edges of the food particles were partially dissolved, and there was moderate muscle fiber rupture. It is estimated that the last meal was 4-6 hours before death. Combined with the time of death, it can be inferred that the deceased's last meal was between 5 pm and 6 pm on August 15th." He examined the deceased's intestines and found "no abnormal food residue in the intestines, ruling out the possibility of death by poisoning."

The deceased's hands also held clues: "There were multiple abrasions on the right palm, with irregular edges, accompanied by mud and black fiber residue," Zhang Kai unfolded the deceased's right hand. "A small amount of skin tissue debris and black fibers were extracted from under the fingernails. Preliminary testing showed the skin tissue to be male, which did not match the deceased's DNA. It is speculated that this was left by the deceased scratching the suspect during the struggle; the nail on the left ring finger was broken, with fresh bleeding at the break, also an injury sustained during the struggle before death." (End of Chapter)