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

The deceased lay flat on the table, his clothes cut open. The electrocution marks on his chest gleamed eerily grayish-white under the cold light, and his left wrist still bore the marks of being wrapped with electrical wires.

“Recording begins,” Zhang Kai said into the recording equipment, using tweezers to pick up a dark blue fiber from the deceased’s collar. “The deceased was male, 178.3 cm tall, with normal development. There were no obvious green spots of putrefaction on the body surface, and rigor mortis was mainly concentrated in the large joints of the limbs.” He pressed his fingers against the deceased’s jaw to feel the degree of muscle relaxation. “The rigor mortis has subsided by about one-third, and the cornea is moderately cloudy. The estimated time of death is between 24 and 36 hours.”

The first incision began on the sternum notch of the deceased. As the scalpel cut through the skin, the yellow of the fat layer contrasted sharply with the pale red of the subcutaneous tissue. "Make a Y-shaped incision," Zhang Kai instructed his assistant, the blade extending along both sides of the collarbone to below the nipples. "Be careful to avoid important blood vessels to prevent blood from contaminating the body cavity." When the skin of the chest and abdomen was turned back, the exposed thoracic organs emitted a faint putrid odor, and the cadaveric green spots on the surface of the liver indicated the progress of decomposition.

"Take a sample of costal cartilage, starting from the seventh rib with a bone saw." Zhang Kai operated the miniature bone saw, the saw teeth rubbing against the bone, producing a harsh sound. The costal cartilage will be sent for radiocarbon dating, one of the important bases for determining the age of the deceased. His gaze turned to the deceased's mouth, using a mouth opener to pry open the lower jaw: "The teeth show obvious wear, the enamel on the incisal edge of the maxillary central incisor is almost worn smooth, and the dentin on the occlusal surface of the first molar is exposed, consistent with the characteristics of an age group of 45-50 years old."

An assistant handed over dental probes, and Zhang Kai carefully examined each tooth: "The lower second premolar has an amalgam filling, which was filled more than ten years ago. The third molar has not fully erupted, and the apical foramen is not closed, indicating a certain difference between physiological age and bone age." He suddenly picked up a foreign object from the gum with tweezers, "and found trace metal fragments, similar to the alloy components of a hydraulic device, which may have been left by the murderer during the crime."

During the examination of the skull, Zhang Kai switched to an electric craniotomy saw. With a hissing sound, white bone fragments flew everywhere. When the complete skullcap was removed, localized liquefaction of the brain tissue was observed. "There is bloody cerebrospinal fluid in the basal cisterns, indicating intracranial hemorrhage," he said. He probed the depression in the skull with a probe. "The occipital bone fracture is scaphoid, with fracture lines radiating outwards, consistent with multiple blunt force trauma. The weapon should be a circular metal object, approximately 4 cm in diameter."

Further examination of the long bones confirmed the age estimation. Zhang Kai cut open the deceased's left femur, and the ratio of red to yellow bone marrow in the medullary cavity indicated a decline in the deceased's hematopoietic function. "By measuring the femur length and calculating using regression equations, the deceased's height before death should have been 177.5-179cm, which matches the actual measurement." He placed the femur under an X-ray machine, and the thickness of the cortical bone and the density of the trabecular bone both pointed to an age range of over 45 years old.

During the examination of the internal organs, Zhang Kai discovered abnormalities. The deceased's heart weighed 380g, and the left ventricular wall was thickened to 1.3cm, indicating myocardial hypertrophy caused by long-term hypertension. "Take myocardial tissue for pathological sections," he said, "to observe whether there are old lesions of myocardial infarction." Fatty degeneration on the surface of the liver and mild enlargement of the spleen also suggested that the deceased had unhealthy lifestyle habits before death.

The most crucial determination of the cause of death comes from a neck autopsy.

The air conditioning, carrying the odor of formaldehyde, circulated among the metal instruments. Zhang Kai's hand, gripping the scalpel, was as steady as a robotic arm. The tip of the blade precisely sliced ​​along the midline of the victim's neck. The instant the skin and tissue separated, dark red blood mixed with pale yellow fatty tissue slowly seeped out, gathering into small streams in the drainage channel. "Observe the morphology of the thyroid cartilage," he instructed his assistant, turning the operating light to its highest brightness. The tip of the tweezers gently lifted the cartilage fragment. "A transverse fracture has occurred in the arch of the cricoid cartilage, and the angle between the two thyroid cartilage plates has widened from the normal 90 degrees to 120 degrees. This characteristic separation only occurs in cases of violent strangulation."

The assistant, holding a magnifying glass, examined the fracture surface of the cartilage at the Adam's apple, revealing irregular serrations and a few muscle fibers still clinging to the fractured bone edges. Zhang Kai probed along the fracture line with a probe, the metal instruments clanging crisply: "The fracture line extends from the cricoid cartilage arch to the lateral plates, indicating a continuous compression from front to back. A brief, violent impact would have resulted in a completely different fracture." He paused abruptly, the tweezers pointing to subcutaneous bleeding points on the cartilage surface. "These purplish-red ecchymoses are marks left by fingertips pressing during strangulation, their diameter roughly the width of an adult male's thumb."

When the trachea was completely separated, a large amount of pink, bloody foam gushed out from the lumen. Zhang Kai caught the sample in a glass dish and held it up to the light source for observation: "This foam has a rich bubble structure, a fine texture, and is not easily broken; it is a typical sign of mechanical asphyxiation." He gently scraped the surface of the foam with a microscope slide. "Under high magnification, these bubbles will show a large number of red blood cells and macrophages. This is because during the asphyxiation process, the lung tissue was damaged due to hypoxia, and blood mixed with respiratory secretions to form this foam."

The assistant flipped through anatomical atlases, finding a corresponding case for comparison: "It's indeed completely different from the appearance of post-mortem neck compression. Post-mortem tracheal contents are more likely to be simple blood deposits, not this foamy structure." Zhang Kai nodded, using tweezers to pick up the mucous membrane tissue from the upper trachea: "More importantly, observe the mucous membrane lacerations here. The wound edges show irregular tears, accompanied by an inflammatory reaction—this means that when the victim was strangled, their physiological functions were still operating, and the respiratory tract produced a protective response."

The corpse on the autopsy table appeared bluish-white under the cold light. Zhang Kai gently pressed along the muscles of the deceased's neck with his fingers: "There are extensive contusions from the trapezius to the sternocleidomastoid muscles, especially bleeding in the carotid triangle area, indicating that the murderer applied tremendous force when strangling the victim." He suddenly pulled up the victim's electrocardiogram record. "Although cardiac arrest was the final cause of death, during the asphyxiation process, the victim experienced a complete pathological process from tachycardia and arrhythmia to ventricular fibrillation, all of which can be verified by the degree of damage to the myocardial cells."

A sudden clanging sound came from the metal instrument tray. Zhang Kai turned to look at the new tools his assistant was preparing: "Next, we'll perform an esophageal dissection to check for reflux of vomit. Victims of mechanical asphyxiation often vomit due to a sudden increase in chest pressure. If stomach contents are found entering the airway, it will further confirm the asphyxiation process." The moment his scalpel sliced ​​through the esophageal wall, a faint, sour smell filled the air. "Remember, every tissue injury is a silent testament left by the deceased. Our job is to decipher these codes." (End of Chapter)