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

"Currently, poisoning is the most likely cause," Zhang Kai said. "We collected blood, stomach contents, liver tissue, and kidney tissue samples from the deceased and sent them to the laboratory for toxicology testing. We focused on testing for common poisons, such as organophosphates, cyanide, sleeping pills, and tetramine, while also testing for alcohol content to rule out alcohol poisoning. In addition, we carefully examined the deceased's mouth, nasal cavity, and ear canals to see if there were any traces of poison residue."

Xiao Lin immediately followed Zhang Kai's instructions, using a sterile syringe to draw blood samples from the deceased, placing them in sealed test tubes and labeling them. Then, using tweezers, she extracted samples of the deceased's stomach contents, liver tissue, and kidney tissue, placing them in sealed bags and labeling them as well. At the same time, she carefully examined the deceased's mouth, nasal cavity, and ear canals, finding no traces of poison residue or abnormal secretions.

"Teacher Zhang, the samples have been collected. Shall we send them to the lab for testing now?" Xiaolin asked.

“Yes, immediately arrange for someone to send the sample to the laboratory and have the laboratory staff conduct expedited testing to get the results as soon as possible. This is the key to determining the cause of death,” Zhang Kai said. “While waiting for the test results, we will continue to conduct a detailed examination of the body to look for other possible clues, such as the deceased’s bones, teeth, hair, etc., to see if there is any information that can prove the deceased’s identity, such as dental treatment marks, skeletal deformities, etc.”

Afterwards, Zhang Kai and Xiao Lin continued to examine the body, focusing on the deceased's bones and teeth. Zhang Kai carefully examined the deceased's teeth with a probe and said, "Xiao Lin, take note: the deceased's teeth are neatly arranged, with no missing or loose teeth, and no obvious cavities. The incisors show slight wear, suggesting that the deceased had a habit of chewing hard objects. There are no obvious treatment marks on the tooth surface, such as fillings or dentures, so we cannot confirm the deceased's identity through dental treatment marks."

"The deceased's skeleton showed no obvious deformities, fractures, or dislocations, and there were no obvious signs of damage on the bone surface. Based on the skeletal morphology, it is impossible to determine the deceased's occupation and identity information. Hair samples have been collected from the deceased, and DNA testing can be conducted later to compare with the missing persons database in an attempt to confirm the deceased's identity."

“Teacher Zhang, there are no items on the deceased’s body that can identify him, and there are no obvious characteristics in his teeth or bones. DNA testing also takes time, so we cannot confirm the identity of the deceased yet. This makes it too difficult to solve the case,” Xiao Lin said, with a hint of frustration in his voice.

Zhang Kai patted Xiao Lin on the shoulder and said calmly, "Don't worry, a forensic doctor's duty is to find as many clues as possible from the body, whether it's the cause of death, the time of death, or clues to the deceased's identity. We must do our best. Although we cannot confirm the deceased's identity yet, as long as we carefully and meticulously perform every examination, we will definitely find clues. In addition, the on-site investigators have extracted fingerprints, fibers, and other trace evidence. If these trace evidences can identify the suspect, we might be able to find the deceased's identity information through the suspect."

Xiao Lin nodded, regained his composure, and continued to assist Zhang Kai in the autopsy. The two conducted a thorough and meticulous examination of the body, finding no other obvious abnormalities. Zhang Kai then began suturing the body, his movements gentle and careful, striving to restore the corpse to its original appearance as much as possible, demonstrating respect for the deceased.

Around 3 a.m., the suturing of the body was completed. Zhang Kai and Xiao Lin organized the dissection tools and collected samples, and properly placed the body in the refrigerated cabinet in the autopsy room. They then began to organize the autopsy records and write the autopsy report. The autopsy report needs to record the deceased's basic information, the external examination, the autopsy findings, the sample collection, and the preliminary determination of the cause and time of death. Every detail must be accurate, and every conclusion must be based on scientific evidence.

"Teacher Zhang, based on the degree of digestion of the food in the deceased's stomach, the ambient temperature at the scene (around 20°C in the afternoon), and the degree of decomposition of the body, we initially determine that the deceased died about 2 to 3 hours before the incident, that is, between 11 pm and 12 pm, is that correct?" Xiao Lin asked while organizing the autopsy records.

Zhang Kai nodded and said, "Yes, that's right. The food in the deceased's stomach has been partially digested. The rice and vegetables have been mostly softened, and there are still a few undigested remnants of meat. Considering the ambient temperature at the scene, as well as the condition of the body's surface—slightly cloudy corneas, initial formation of rigor mortis, and pale purple lividity on the back and hind limbs—we can conclude that the deceased died 2 to 3 hours before the incident, which is between 11:00 AM and 12:00 PM on [Date]. The exact time of death will require further analysis of laboratory toxicology results and autopsy."

"What is the cause of death? Our preliminary assessment is poisoning, but we still need to wait for the laboratory test results to determine the specific type and dosage of poisoning, right?"

“Yes,” Zhang Kai said. “Currently, we have ruled out organ damage, disease, intracranial injury, and asphyxiation as causes of death. Based on the condition of the body's surface and internal organs, we have preliminarily determined that the deceased died of poisoning. However, the specific type of poisoning—organophosphates, cyanide, sleeping pills, etc.—and the dosage still need to be determined by laboratory testing of extracted blood, stomach contents, liver tissue, and other samples. In addition, we also need to rule out the possibility of suicide and accidental poisoning. Based on the scene investigation, the deceased was found in a material storage area at a subway construction site. The scene was remote, and the deceased had blunt force trauma and torn clothing, suggesting that homicide is more likely. However, a final judgment will be made based on investigative clues and test results.”

Xiao Lin carefully recorded Zhang Kai's words and then began writing the autopsy report. Every detail was meticulously recorded according to the autopsy procedure to ensure the report's authenticity, accuracy, and compliance with regulations. Zhang Kai, meanwhile, carefully reviewed Xiao Lin's autopsy report, promptly pointing out any problems and having Xiao Lin revise it to ensure the report was free of any omissions.

Around 5 a.m., the preliminary autopsy report was completed. The report detailed the deceased's basic information, external physical examination, autopsy findings, and sample collection. The preliminary conclusion was that the deceased died of poisoning, between 11 a.m. and 12 p.m. on [Date], 2 to 3 hours prior to the incident. (End of Chapter)