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

The two then focused their examination on the deceased's neck, the core area for determining whether strangulation had occurred. "The skin on the deceased's neck is intact; no obvious ligature marks were found?" Xiao Lin said with some doubt after a careful examination. Zhang Kai leaned closer to observe, gently pressing his fingers on both sides and the front and back of the deceased's neck: "Don't rush. Some ligature marks may not be obvious on the surface of the body due to clothing or the special material of the ligature. Shine a multi-band light source on the neck to see if there are any hidden ligature marks."

Xiao Lin immediately retrieved a multi-wavelength light source, adjusted the wavelength, and shone it on the deceased's neck. Under the specific wavelength of light, faint, dark purple ligature marks appeared on the front and sides of the deceased's neck. These marks were horizontal, encircling the neck, approximately 1.2 cm wide, and varied in depth, with the left side being deeper and the right side slightly shallower. "Teacher Zhang, ligature marks have appeared!" Xiao Lin exclaimed excitedly. Zhang Kai nodded: "Measure the length, width, and depth of the ligature marks, and record their direction, shape, and characteristics."

"The ligature groove encircles the neck, approximately 35cm in length and 1.2-1.5cm in width. The deepest point of the groove on the left is about 0.3cm, and on the right it is about 0.15cm. The edges of the groove are neat, with no obvious skin peeling or rigging patterns," Xiaolin noted as she measured. Zhang Kai added, "These characteristics of the ligature groove suggest that the tool used was likely a soft, relatively uniformly wide strip of material, such as a strip of cloth, tie, or belt. Furthermore, the force applied during the crime was uneven, with more force applied to the left side. Additionally, the absence of obvious skin peeling in the groove may be due to clothing covering the skin or the ligature being relatively smooth."

After examining the neck, the two examined the deceased's chest and abdomen. "The chest and abdomen are symmetrical, with no obvious bulging or depression, and no signs of subcutaneous hemorrhage or rib fractures were found. There were no wounds or contusions on the abdomen," Xiaolin said. Zhang Kai pressed on the deceased's chest and abdomen with his hand: "The ribcage is elastic, and there is no feeling of bone friction, which initially rules out the possibility of blunt force trauma or compression to the chest and abdomen. Next, we will conduct an autopsy, focusing on examining the soft tissues of the neck, pharynx, trachea, and lungs to confirm the cause of asphyxiation. At the same time, we will examine the thoracic and abdominal organs to rule out other causes of death."

Holding a scalpel, Zhang Kai made a standard Y-shaped incision in the deceased's chest and abdomen, starting from both sides of the shoulders, converging at the xiphoid process of the sternum, and then extending downwards to above the pubic symphysis. The blade sliced ​​through the skin and subcutaneous tissue, clearly exposing the bloodied and mangled subcutaneous fat and muscle tissue. "Observe carefully the color of the subcutaneous tissue and muscle, for any bleeding or abnormal infiltration," Zhang Kai said. Xiao Lin carefully observed: "The subcutaneous fat is pale yellow, and the muscle tissue is dark red, with no obvious bleeding foci or abnormal infiltration, consistent with the tissue state after normal death."

Zhang Kai then used rib shears to cut the deceased's ribs, opening the chest cavity and exposing the organs inside. "Both lungs were of normal volume, dark red in color, soft in texture, and smooth in surface; no ruptures, bleeding, or nodules were found." Zhang Kai lifted the lungs with forceps and examined them carefully. "Upon cutting open the lung tissue, no foamy fluid was found, ruling out drowning as the cause of death. The lung weights were measured: the left lung approximately 550g, and the right lung approximately 600g, both within the normal range."

"Teacher Zhang, in cases of death by suffocation, are there any unusual changes in the lungs?" Xiao Lin asked. Zhang Kai explained, "In cases of death by strangulation, the lungs will show congestion and edema due to airway obstruction. However, these changes are not specific; they can also occur in other causes of death. The key is to combine this with changes in the soft tissues of the neck, the throat, and the trachea for a comprehensive assessment." After explaining, he temporarily set the lungs aside and began examining the heart and major blood vessels.

"The heart is of normal size, weighing approximately 350g, with a small amount of fatty infiltration on the surface. There is no obvious stenosis in the coronary arteries, and no bleeding points in the epicardium." Zhang Kai used a scalpel to cut open the heart and observe the inside of the heart chambers. "The inner walls of the heart chambers are smooth, the myocardial tissue is dark red, there are no infarct foci or hemorrhage foci, and there is a small amount of coagulated blood in the heart chambers, consistent with post-mortem coagulation." After ruling out death due to heart disease, Zhang Kai refocused his attention on the neck, which was the core focus of this autopsy.

He carefully used tissue scissors to cut open the skin and subcutaneous tissue of the deceased's neck, exposing the neck muscles, blood vessels, and nerves. "Xiao Lin, carefully observe the neck muscles for bleeding, especially the sternocleidomastoid muscle and the infrahyoid muscle group," Zhang Kai reminded him as he worked. Xiao Lin leaned closer to observe and quickly made a discovery: "Teacher Zhang, there is a patchy hemorrhage in the middle of the left sternocleidomastoid muscle, covering an area of ​​about 3cm × 2cm, and there are also a few punctate hemorrhages in the right sternocleidomastoid muscle!"

“These are important signs of death by asphyxiation,” Zhang Kai said. “Hemorrhage in the sternocleidomastoid muscle is usually caused by the violent contraction of the neck muscles during asphyxiation, or by the suspect forcefully pressing or pulling on the neck. Continue to examine the hyoid bone, thyroid cartilage, and cricoid cartilage for fractures.” Xiao Lin lifted the hyoid bone with tweezers and examined it carefully with a magnifying glass: “There is no obvious fracture of the hyoid bone, there is a slight bone crack at the upper corner of the thyroid cartilage, and the cricoid cartilage is intact.”

Zhang Kai nodded: "Fragments of the hyoid bone and thyroid cartilage are common signs of strangulation death, but not all strangulation deaths will show these signs. This is related to the material of the ligament, the force applied, and the duration of the injury. The deceased had a fracture of the superior angle of the thyroid cartilage, which, combined with the ligament groove in the neck and bleeding in the sternocleidomastoid muscle, further confirms the possibility of strangulation. Next, examine the throat and trachea to see if there is any foreign object obstruction or mucosal damage."

He used tissue scissors to cut open the pharyngeal mucosa, exposing structures such as the epiglottis and glottis: "The epiglottic mucosa was intact, without congestion, edema, or damage; the glottic mucosa had mild congestion, but no foreign body obstruction was observed." Subsequently, he continued to cut down the trachea, "The tracheal mucosa was smooth, without obvious congestion, edema, or bleeding, and there were no secretions or foreign body residues in the lumen, ruling out the possibility of suffocation caused by foreign body obstructing the airway."

Xiao Lin asked疑惑地问道, "Teacher Zhang, since there were no foreign objects in the trachea and no obvious mucosal damage, how can you be sure it was strangulation?" Zhang Kai patiently explained, "The core mechanism of strangulation is that the rope compresses the neck, blocking the airway and major blood vessels in the neck, leading to hypoxia and suffocation. Not all strangulation deaths show tracheal mucosal damage, especially when the rope is soft and the impact time is short; the tracheal mucosa may only show slight congestion or even no obvious changes. By combining these signs—the ligature groove on the deceased's neck, bleeding in the sternocleidomastoid muscle, fracture of the thyroid cartilage, and subconjunctival hemorrhages in both eyes—we can clearly determine the cause of death as strangulation." (End of Chapter)