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

Zhang Kai picked up a ruler and carefully measured the three wounds precisely. At the same time, he used a magnifying glass to carefully observe the shape, edges, and depth of the wounds. He said in a serious tone, "Xiao Lin, observe carefully and record the specific data of each wound, including the length, width, depth, direction, shape, and details of the wound edge, wound wall, and wound cavity. This is directly related to the judgment of the murder weapon and the analysis of the angle and force of the stab."

"Received, Teacher Zhang!" Xiaolin held her breath, leaned close to the wound, carefully observed every detail, and made notes.

“The first wound is located in the fourth intercostal space on the left side of the sternum, 2.5 centimeters from the midclavicular line,” Zhang Kai described in detail while taking measurements. “The wound is 2.8 centimeters long and 0.8 centimeters wide. The wound edges are neat, with no epidermal contusions, smooth wound walls, and no tissue debris. The wound cavity is 8.2 centimeters deep. The wound direction is from the upper right to the lower left, forming a 30° angle with the horizontal plane. The wound cavity has no branches, does not penetrate the pleural cavity, and does not damage any organs within the pleural cavity. It only damages the chest wall muscles and subcutaneous tissue, with a small amount of bleeding. It is a non-fatal injury.”

"Record: First wound, fourth intercostal space on the left side of the sternum, 2.5 cm from the midclavicular line, 2.8 cm long, 0.8 cm wide, with neat edges and smooth walls, 8.2 cm deep, oriented from the upper right to the lower left at a 30° angle to the horizontal plane, did not penetrate the pleural cavity, non-fatal injury, damaged chest wall muscles and subcutaneous tissue." Xiaolin quickly recorded the information while taking pictures of the wound details to ensure that every piece of data was clearly accurate.

“The second wound is located in the fifth intercostal space on the left side of the sternum, 3 centimeters from the midclavicular line,” Zhang Kai continued to measure and observe, his tone becoming increasingly rigorous. “The wound is 3.1 centimeters long and 0.8 centimeters wide, with neat edges and smooth walls. The wound cavity is 9.5 centimeters deep. The wound direction is from the upper right to the lower left, forming a 35° angle with the horizontal plane. The wound cavity has no branches, penetrates the pleural cavity, and punctures the upper lobe of the left lung, causing rupture and bleeding in the upper lobe of the left lung. This is an auxiliary fatal wound that accelerated the victim’s death process.”

“Teacher Zhang, I see a small amount of blood clots and some lung tissue fragments in the wound cavity,” Xiao Lin carefully observed the inside of the wound cavity and added earnestly, “The wound wall has no obvious roughness, which means that the blade of the murder weapon is sharp, without nicks or abnormal wear, which is consistent with the characteristics of a single-edged sharp weapon.”

“That’s right,” Zhang Kai nodded slightly, acknowledging Xiao Lin’s assessment. “Record: Second wound, fifth intercostal space on the left side of the sternum, 3 cm from the midclavicular line, 3.1 cm long, 0.8 cm wide, with neat edges and smooth walls, 9.5 cm deep, directed from the upper right to the lower left at a 35° angle to the horizontal plane, penetrating the pleural cavity, puncturing the upper lobe of the left lung, causing rupture and bleeding in the upper lobe of the left lung, an auxiliary fatal wound, with blood clots and lung tissue fragments remaining in the wound cavity, and the blade of the murder weapon was sharp.”

Zhang Kai then focused his attention on the third wound, which was also the most likely fatal injury: "The third wound is located in the third intercostal space on the left side of the sternum, 2 centimeters from the midclavicular line. This is the key point; observe it carefully. The wound is 2.9 centimeters long and 0.8 centimeters wide, with neat edges and smooth walls. The wound cavity is 10.3 centimeters deep. The direction of the wound is from the upper right to the lower left, forming a 28° angle with the horizontal plane. The wound cavity has no branches, penetrates the pleural cavity, and punctures the left ventricle of the heart. There are a large number of blood clots and myocardial tissue fragments remaining in the wound cavity. The left ventricle of the heart has ruptured, and the ventricular wall wound is about 2.5 centimeters long and about 0.7 centimeters wide, causing massive cardiac hemorrhage. This is the fatal injury and the direct cause of the deceased's death."

While taking notes, Xiaolin couldn't help but ask, "Teacher Zhang, the width of the three wounds is about 0.8 centimeters, and the direction is roughly the same. Does this mean that the murderer used the same knife to stab them? Moreover, the stabbing angles are relatively fixed. Does this reflect the murderer's height, build, and stabbing posture?"

“Your observation is very meticulous,” Zhang Kai nodded approvingly, explaining patiently, “The width, edge shape, and wall characteristics of the three wounds are completely consistent, which confirms that they were caused by the same single-edged sharp weapon. Combined with the carbon steel metal residue and metal fragments extracted from the scene, as well as the preliminary test results from the laboratory, we have further confirmed that the murder weapon was a single-edged carbon steel knife, with a blade length of about 12 centimeters and a width of about 0.8 centimeters. The blade is sharp, without nicks or wear, and the handle may have a handguard (the metal fragments extracted from the scene are preliminarily identified as handguard fragments).”

After a pause, Zhang Kai continued his analysis: "As for the angle of the stabs, all three wounds are from the upper right to the lower left, with an angle between 28° and 35°. The relatively fixed angle indicates that when the perpetrator stabbed the victim, his body was positioned to the upper right of the victim, and his height should be slightly taller than the victim. Based on the scene investigation, the victim's height is about 175 cm, so it is estimated that the perpetrator's height is between 178 and 182 cm, with a medium build. He was standing when he stabbed the victim, with his arm hanging naturally and the force applied evenly. All three stabs accurately hit the intercostal area of ​​the chest, indicating that the perpetrator may have some knowledge of human anatomy or have similar experience in committing crimes, and that the stabbings were not random. In addition, the three wounds are evenly spaced, about 2 cm apart, indicating that the perpetrator's hand was stable and there was no obvious tremor when he stabbed the victim, ruling out the possibility that he committed the crime under the influence of alcohol or drugs, as well as the possibility that the perpetrator's excessive tension caused the stabbing deviation."

"Understood, Teacher Zhang!" Xiao Lin suddenly realized and quickly added Zhang Kai's analysis to the autopsy record. "I will focus on recording the characteristics of the murder weapon, including the angle and force of the stabs, to provide a reference for subsequent case investigations. Also, the bloodstains on the victim's chest covered a large area. Could it be due to a large amount of blood gushing out after the heart ruptured, coupled with bleeding from a ruptured left lung, resulting in double bleeding?"

“Yes,” Zhang Kai nodded in confirmation. “The heart is the core of the human body’s blood supply. After the left ventricle ruptures, a large amount of blood in the heart will gush out under the influence of blood pressure. In addition, the bleeding from the rupture of the upper lobe of the left lung caused the victim to lose too much blood in a short period of time. This is the main reason for the victim’s rapid death. The large pool of blood on the ground was formed by the large amount of blood flowing out after the heart and lungs ruptured. This is completely consistent with the wound and internal organ damage we have observed so far, further confirming the preliminary judgment of the on-site investigation.”

After completing the physical examination and wound analysis, Zhang Kai took a deep breath and said to Xiao Lin, "The physical examination and wound analysis are finished. Now we will begin the formal autopsy. We will open the thoracic and abdominal cavities, and the cranial cavity layer by layer, to comprehensively examine the internal organs and the brain, collect various samples, and focus on analyzing the stomach contents, blood, heart, lungs, liver, and brain to accurately estimate the time of death and confirm the cause of death. At the same time, we will check for any other potential injuries, any residual toxins, and look for clues to confirm the identity of the deceased. Remember, during the autopsy, you must follow the proper procedures to avoid causing secondary damage to the internal organs. Every examination of every organ and every sample collected must be carefully recorded. There can be no carelessness." (End of Chapter)