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

He told Kobayashi, "High temperature is the external force that interferes with the gears, causing the pointer to move fast and slow. What we need to do is find their original speed." The moonlight outside the window shone through the blinds, casting dappled light on the report. The precisely calculated numbers seemed to be silently telling the exact moment when the deceased stopped breathing.

The examination of the stomach contents provided important information. In the cleaned stomach tissue, small amounts of incompletely digested rice and meat fibers remained. "The rice grains had a hydrolysis rate of about 40%, and the meat fibers had relatively clean fracture surfaces," Zhang Kai observed under a microscope. "This is the state of digestion 4-6 hours after eating. Assuming dinner was between 18-20 PM, the time of death should be calculated to be between 22 PM and 2 AM the next day." He suddenly pointed to the duodenum, "The intestinal contents began to move into the jejunum, further supporting this timeframe."

The bone marrow test results also confirmed this. A smear of femoral bone marrow revealed that the nucleated cells showed moderate degeneration, and the lactate dehydrogenase activity was 60% of normal. "The enzyme activity in the bone marrow begins to decline 12 hours after death, decreasing by about 20% every 12 hours," Zhang Kai calculated. "The current activity of 60% corresponds to a time of death of about 24 hours, which is basically consistent with the inference from the gastric contents."

The most crucial cause of death was determined after blood toxicology analysis. "Carboxyhemoglobin saturation of 35% is not lethal," Zhang Kai pointed to the values ​​on the report, "but cyanide was detected in the blood, reaching a concentration of 0.8 mg/L, which is the lethal dose threshold." Xiao Lin gasped: "So, he was first poisoned by inhaling cyanide, and then he was cremated?" Zhang Kai nodded: "During cremation, nitrogen-containing organic matter burns to produce cyanide, but if it was inhaled before death, the concentration in the blood wouldn't be this high and evenly distributed. It's more likely that he was forcibly given or inhaled a high concentration of cyanide before cremation, leading to respiratory depression, before being burned."

He suddenly recalled the findings from the autopsy and used a probe to examine the skin defect on the chest again: "Although the tissue here is charred, there are signs of bleeding in the muscle layer at the edges, indicating that the injury occurred before death. Combined with the conclusion of cyanide poisoning, it cannot be ruled out that he was struck with a blunt object and lost the ability to resist before being poisoned and burned." The scalpel gently cut open the defect, revealing a small metal fragment under the charred muscle tissue—its shape matched that of the cement nail found at the scene.

As the last stitch pierced the skin, moonlight streamed through the blinds onto the autopsy table. "Summary of cause of death: cyanide poisoning combined with carbon monoxide poisoning," Zhang Kai wrote in the report. "The deceased suffered blunt force trauma (chest injury), was forcibly ingested or inhaled cyanide leading to poisoning and coma, was subsequently set on fire, and ultimately died from respiratory and circulatory failure." He paused, then added, "After comprehensive adjustments, the time of death is determined to be between 10 PM on May 12th and 2 AM on May 13th, with an error margin of no more than 4 hours."

While sorting through the evidence, Xiaolin suddenly discovered a small fragment of tissue in the gap between the gears of a watch. "Teacher Zhang, there's what looks like skin tissue residue here!" She carefully extracted it with a sterile cotton swab. "Although it was damaged by the high temperature, we might be able to extract DNA." Zhang Kai took the evidence bag, his gaze falling on the night sky outside the window: "This watch stopped at 11:05, which is very likely the moment he died of poisoning, and this fragment of tissue might be the key to identifying the murderer."

The clock in the autopsy room struck four in the morning. Zhang Kai watched as his assistant classified and labeled all the samples, then suddenly said, "Have the trace evidence department look at that cement nail tomorrow," his voice weary. "If they can find tissue on it that matches the deceased's, we'll have a complete chain of evidence." Xiao Lin nodded and put the last blood sample into the refrigerator. "Professor Zhang, why do you think the murderer went to so much trouble, poisoning and burning it?"

Zhang Kai stared at the body covered with a white sheet on the autopsy table and remained silent for a moment: "Either the hatred was extremely deep, or they wanted to completely destroy the evidence." His fingers tapped lightly on the words "cyanide." "This highly toxic chemical is not easy to obtain, which means that the murderer had certain channels and premeditation, and it was definitely not a spur-of-the-moment decision."

Footsteps echoed down the corridor, and Lu Chuan appeared in the doorway. "Any results?" His voice was expectant. Zhang Kai handed him the preliminary report: "The death was a homicide. The time and cause of death have been determined, and key evidence is being tested." Under the light, the words "cyanide poisoning" on the report gleamed coldly, like the eyes hidden behind this case, coldly watching everyone who tried to uncover the truth.

Meanwhile, Zhang Hui was investigating the deceased's identity. As he downed his 17th cup of instant coffee, the brown liquid churned in his stomach, a stark contrast to the bloodshot eyes. "Entry 893," his fingers slid across the mouse, the missing persons database interface flashing on the screen, "Chen Ming, male, 35 years old, self-employed, missing May 11th, distinguishing feature: a mole on his left eyebrow." He typed "excluded" on the keyboard, his pen drawing a heavy line across his notebook—this was the 23rd suspected case eliminated that night.

Young officer Zhao rubbed his aching shoulders, the chair scraping against the floor with a screeching sound. "Brother Hui, want to take a break?" The aroma of goji berries wafted from his thermos, mingling with the cigarette smoke in the air to create an odd smell. "This system is slower than an old tape recorder. Over 1000 messages, my eyes are practically crossed." Zhang Hui didn't look up, pointing to the photo on the screen: "Look closely, the deceased was 172cm tall, 30-40 years old. The forensic doctor said he probably had a respectable job; his fingers were well-maintained, even with charring, you can still see some traces."

At one in the morning, the office was filled with the sounds of snoring. Veteran detective Zhou Jianguo dozed off, his drool smearing the words "Cause of Disappearance: Out and Not Returning"; Xiao Wang from the technical department spread his coat on the table, curled up like a shrimp, clutching the corner of the preliminary DNA comparison report. Zhang Hui suddenly slammed his hand on the table, the photo on the screen instantly waking him—it was a man in a suit, wearing a stainless steel watch on his left wrist, the style extremely similar to the one found at the scene, dated May 12th. "This one!" His voice startled the sparrows on the windowsill. "Liu Yuan, male, 38 years old, corporate executive, disappeared on May 12th, 173cm tall, distinguishing feature is the stainless steel watch on his left wrist!"

Xiao Zhao sprang up from his chair, the mouse cable snapping straight in his hand. "Compare the autopsy report," his fingers flew across the keyboard, "there were indeed remnants of a stainless steel watch on the deceased's left wrist; the location and size match!" (End of Chapter)