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

Xiao Lin immediately opened the dissection instrument box, took out a scalpel, rib shears, hemostats, and other instruments, and handed them to Zhang Kai. Holding the scalpel, Zhang Kai made a standard "Y"-shaped incision along the midline of the sternum from the lower edge of the mandible to above the pubic symphysis on the deceased's chest. The blade made a slight "hissing" sound as it cut through the skin. He then used the hemostats to separate the subcutaneous tissue and muscle, exposing the sternum and ribs.

"Observe the subcutaneous bleeding carefully," Zhang Kai said as he separated the tissue. "There is no abnormal bleeding in the subcutaneous tissue, and the muscle tissue is pale, which is consistent with death from hemorrhagic shock." He then used rib shears to cut the ribs on both sides of the sternum, carefully removing the sternum along with the ribs to expose the internal organs of the chest cavity. The moment the chest cavity was opened, a faint smell of blood filled the dissection room.

"There is a small amount of blood in the pleural cavity, about 150 ml. The blood is dark red and has not coagulated." Zhang Kai used a suction device to remove the blood from the pleural cavity and carefully observed the morphology of the pleural organs. "Both lungs are of normal volume and pale in color, with no rupture or bleeding; the heart is enlarged, with a small amount of punctate hemorrhage under the epicardium, and there is a wound on the anterior wall of the left ventricle that penetrates the ventricular wall." He gently lifted the heart with dissecting forceps. "Xiao Lin, measure the size and depth of the wound."

Xiao Lin took out calipers and carefully measured: "Teacher Zhang, the wound is 5.2 cm long and 1.6 cm wide, with one blunt and one sharp angle, the sharp end facing left and the blunt end facing right. The wound depth is 8.5 cm, penetrating the left ventricular wall and reaching the heart chamber." Zhang Kai nodded: "The wound has one blunt and one sharp angle, with neat edges, no epidermal abrasion or contusion. This is a typical single-edged sharp instrument stab wound, perfectly matching the single-edged dagger retrieved from the scene. The wound is located on the anterior wall of the left ventricle, a critical part of the heart. The stab depth of 8.5 cm is sufficient to damage the heart's major blood vessels, leading to massive blood loss and heart failure."

"Can we preliminarily determine the cause of death as hemorrhagic shock?" Xiao Lin asked. Zhang Kai shook his head: "We can't draw a conclusion too early. We need to consider the condition of other organs and information such as the bloodstains found at the scene. Yang Lin and his team found medium-velocity bloodstains at the scene, indicating that the deceased still had vital signs and the heart was still pumping blood when the stabbing occurred. This is consistent with the characteristics of death from hemorrhagic shock caused by a cardiac wound. However, we still need to check for other causes of death, such as suffocation or poisoning."

Zhang Kai then began examining the deceased's respiratory and digestive tracts. He separated the neck tissue to expose the trachea and esophagus: "The tracheal mucosa was smooth, with no foreign body obstruction or bleeding points, ruling out death due to mechanical asphyxiation." Next, he opened the deceased's abdominal cavity and examined organs such as the liver, spleen, stomach, and intestines: "The liver was pale and without rupture or bleeding; the spleen was of normal size and soft in texture; the intestines showed no abnormal dilation or bleeding."

“Focus on examining the stomach contents.” Zhang Kai used a scalpel to cut open the deceased’s stomach wall. Inside, there was a small amount of semi-digested food residue, mainly rice, vegetables, and a small amount of meat. “The stomach contents weighed about 200 grams, and were semi-liquid. The food was partially digested, but the shape of the rice and vegetables was still recognizable.” He used tweezers to take a small sample of the stomach contents and placed it in an evidence bag labeled “Stomach Contents-001.” “Based on the degree of digestion of the stomach contents, the deceased should have died 3-4 hours after eating.”

Xiao Lin immediately wrote it down and asked, "Teacher Zhang, considering the previous findings on body temperature, rigor mortis, and corneal opacity, along with the degree of digestion of the stomach contents, can we accurately determine the time of death?" Zhang Kai pondered for a moment: "Looking at all the indicators, the rate of decrease in body temperature, the stage of rigor mortis, and the degree of corneal opacity all point to 4-5 hours after death, while the degree of digestion of the stomach contents indicates death 3-4 hours after eating. Let's assume the deceased ate around 22 PM last night, then the time of death should be between 1 AM and 2 AM this morning; if the eating time was slightly later, such as 23 PM, then the time of death would be between 2 AM and 3 AM. Combining the bloodstains and footprints found by Yang Lin and his team at the scene, the suspect fled along the west staircase after committing the crime. The bloodstains along the way were stable in shape, indicating that he did not run frantically after committing the crime. We speculate that the time of the crime should be between 1 AM and 3 AM, which perfectly matches the time of death range obtained from our autopsy."

"So the cause of death can be determined as hemorrhagic shock caused by a single-edged sharp object piercing the left ventricle, right?" Xiaolin asked again to confirm. Zhang Kai nodded: "Yes. After a full autopsy, the deceased only had one fatal wound on his chest, caused by a single-edged sharp object that pierced the left ventricle, resulting in massive blood loss and ultimately leading to hemorrhagic shock and death. No other causes of death were found, ruling out asphyxiation, poisoning, or death from rupture of other organs."

Next, Zhang Kai and Xiao Lin began a more detailed external examination and autopsy of the body, looking for clues that might lead to the identity of the deceased or the suspect. Zhang Kai examined the deceased's teeth: "The teeth are neatly arranged, without cavities or dentures, and the wear on the teeth is relatively light. Based on the bone development, we initially judged the deceased to be between 38 and 42 years old, which is basically consistent with Yang Lin and his team's initial assessment at the scene that the age range was 35 to 45."

Xiao Lin examined the deceased's fingernails: "The deceased's fingernails were of moderate length, and there was a small amount of dust and fiber in the nail crevices, which is consistent with the nail crevices sample taken from the scene. The fingernails had no obvious damage and no scratches left from the struggle, indicating that the deceased may not have put up a strong resistance when stabbed, or the resistance time was short."

Zhang Kai added, "At the scene, Yang Lin and his team found that the deceased's hands were clenched into fists, with a small amount of fiber under the fingernails. Combined with the wounds on the body, they speculated that the deceased had briefly resisted when stabbed, but because the suspect stabbed a vital area of ​​the heart, the deceased quickly lost the ability to resist and ultimately died." He then examined the deceased's entire body and found no other wounds, bruises, binding marks, or restraint marks, further ruling out death caused by other acts of violence.

"Teacher Zhang, should we collect the deceased's DNA and fingerprints for comparison with the physical evidence collected at the scene?" Xiao Lin asked. Zhang Kai nodded: "Of course. We'll collect a venous blood sample from the deceased for DNA typing and compare it with the bloodstains found at the scene to confirm if the bloodstains belonged to the deceased; at the same time, we'll collect the deceased's fingerprints and compare them with the fingerprint samples collected at the scene to rule out any interference from the deceased's fingerprints in the investigation of suspects. In addition, we'll collect samples of the deceased's hair, nails, etc., for further testing." (End of Chapter)