The crackdown on organized crime began with the arrest of the mother-in-law.

Chapter 852 Technical Analysis, Autopsy

The investigation is ongoing. Detective Li, who is conducting the on-site investigation, and detective Wang, who is using technical expertise, are engaged in in-depth discussions and analysis of the various clues.

Xiao Li frowned, staring at the slightly messy grapevines on the ground, crushed by the corpse, and said to Xiao Wang, "Xiao Wang, this scene looks tricky. We need to find the key from these fragmented clues. Let's start with bloodstain analysis; it's extremely important for reconstructing the crime scene."

Xiao Wang nodded, squatted down, picked up the bloodstain testing reagent, and said, "That's right, Xiao Li. I'll collect these suspected bloodstain samples first. Judging from the scene, the bloodstains are concentrated around the body, but there are a few drops of blood that are sprayed outwards towards the grape trellis. I speculate that the deceased was standing when he was fatally attacked, and the murderer attacked from a specific angle, resulting in the bloodstains being distributed in this way."

Following the direction Xiao Wang was pointing, Xiao Li looked and asked, "Can we determine when the bloodstains were left from their color and dryness? This would help in determining the time of the incident."

While operating the equipment, Xiao Wang responded, "Sure, I'll collect the sample and take it back to the lab. Using luminol reagent and a spectrophotometer, we can measure the fluorescence intensity produced by the reaction of iron ions in hemoglobin with the reagent, and then, based on the Arrhenius equation and considering environmental factors such as temperature and humidity, we can accurately estimate the time of bloodstain formation. However, we'll have to wait until we get back to the lab for detailed analysis."

After cleaning up the bloodstains, the two turned their attention to the body. Xiao Li gently lifted the deceased's hand and said, "This black substance under the deceased's fingernails looks strange. It might be a key clue, left by the deceased when the murderer resisted during the crime."

Xiao Wang took out tweezers, carefully collected a sample of the black substance, and placed it in a special evidence bag. He said, "I will use a scanning electron microscope (SEM) combined with an energy dispersive spectroscopy (EDS) to analyze it. By bombarding the sample with an electron beam, I can observe its microstructure and determine its elemental composition. If we can find any special substances related to the murderer's clothing or the murder weapon, the case might have a major breakthrough."

The next step is to determine the exact time of death. Xiao Li looked at forensic doctor Zhang Lin and asked, "Forensic doctor Zhang, this body is highly decomposed, making it difficult to determine the time of death. Do you have any suggestions?"

Zhang Lin pushed up her glasses, her expression focused, and said, "I'll start by judging from the degree of decomposition. The body is in a state of grotesque decay, with an swollen abdomen and obvious green spots on the skin. My initial estimate is that the body has been dead for more than a week. But this is just a rough estimate."

Xiao Wang added, "Forensic Doctor Zhang, I can assist in the diagnosis by testing the chemical changes in the body's tissues. For example, we can test the potassium ion concentration in the vitreous humor. As the time of death progresses, the potassium ion concentration gradually increases. Based on this pattern of change, combined with the temperature and humidity of the environment in which the body was located, we can establish a mathematical model to more accurately estimate the time of death."

Zhang Lin nodded in agreement: "That's right, Xiao Wang. In addition, I will dissect the body to check the degree of digestion of the stomach contents. If there is a lot of food residue in the stomach and it is not completely digested, it means that the time of death is closer to the last meal; conversely, if it is completely digested, then the time of death is longer. By making a comprehensive judgment from these aspects, we can narrow down the time of death as much as possible."

At this moment, Xiao Zhao, the technician in charge of DNA identification, arrived and said, "I brought the hair, dander, and other samples collected at the scene back to the lab. We used polymerase chain reaction (PCR) to amplify the DNA fragments, then separated them by capillary electrophoresis and compared them with the database. However, the body was highly decomposed, and the DNA was severely degraded, making it difficult to extract complete and usable DNA, but we will do our best."

Xiao Li frowned and asked worriedly, "How confident are we in obtaining valid DNA? If we can't identify the deceased, the case will be very difficult to solve."

Xiao Zhao said confidently, "We have advanced second-generation sequencing technology. Even if the DNA degrades, we can still piece together the fragmented DNA by optimizing the experimental conditions and repeating the experiment multiple times. As long as there is even the slightest possibility, we will never give up."

Back in the police station lab, Xiao Wang was carefully examining the black substance sample under a scanning electron microscope. Xiao Li, waiting anxiously beside him, asked, "Xiao Wang, are there any results for this black substance?"

Xiao Wang excitedly said, "We've made a discovery! This substance contains special fiber components. After comparing it with common industrial materials, we initially determined that it is a kind of high-strength engineering plastic, which may have come from the murderer's tools or clothing. This is an important clue."

Despite some key progress made in the initial forensic analysis, the identification of the deceased encountered unexpected difficulties. It was initially thought that DNA testing, combined with a missing persons database, would quickly pinpoint the victim's identity; however, contrary to expectations, no matching individuals were found in the database. This result cast a shadow over the entire task force.

Undeterred, the officers responsible for identification quickly shifted their focus, deciding to start with the body's physical characteristics and clothing. They meticulously compiled detailed information about the deceased, including facial contours, hairstyle, and any noticeable birthmarks or scars. They also carefully recorded the style, material, brand, and any distinctive markings on the clothing. Subsequently, the officers compared this information with recently reported missing persons records.

That night, no one in the Criminal Investigation Division rested; everyone was fully immersed in this tedious work. They stared at their computer screens, repeatedly reviewing missing persons reports, meticulously comparing the descriptions in the reports with the actual circumstances of the deceased. No detail was overlooked, and every clue was carefully verified. However, after a thorough investigation of the 15 missing persons, no matching information was found. The confirmation of the deceased seemed to have reached a dead end, and the investigation had temporarily stalled.

Meanwhile, Zhang Lin had transported the body back to the Criminal Investigation Division and begun the autopsy. Inside the autopsy room, the lights were stark, and the atmosphere was heavy. Zhang Lin, dressed in professional dissection gowns, a mask, and gloves, stood with focused and resolute eyes. She stood before the dissection table, various dissection tools laid out beside her, each gleaming with a cold metallic sheen.

Zhang Lin first re-examined the body's surface, dictating to her assistant as she did so: "The body is in a highly decomposed state, with loose skin and some areas of sloughed-off skin. No obvious open wounds were found on the head, but a large hematoma can be felt under the scalp, suggesting a violent impact to the head before death." She picked up a scalpel and carefully made incisions along the body's midline. As the scalpel moved, the skin was slowly separated, revealing the already decaying muscle tissue beneath.