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

"Captain Lu, the DNA testing is still in progress. We expect to complete all the comparisons and get the final results around 3 p.m. I will report to you as soon as I have any news," Zhang Kai said.

"Okay, thank you for your hard work, Forensic Doctor Zhang! Please continue to follow up on the DNA testing and further examination of the fiber samples. Contact me immediately if you have any news."

"Understood, Captain Lu!" After hanging up the phone, Zhang Kai and Xiao Lin continued their work. They conducted further examinations on the fiber samples, analyzing the specific source of the fibers in an attempt to find relevant clues about the suspect. At the same time, they awaited the final results of the DNA test, hoping to confirm the deceased's identity through DNA comparison.

Meanwhile, in the conference room of the Dongcheng Criminal Investigation Detachment, Lu Chuan was holding an emergency meeting to deploy subsequent investigative work. "Comrades," Lu Chuan said firmly, "based on the forensic doctor Zhang's autopsy report, we have determined that the deceased died from methamidophos poisoning. The time of death was approximately 11:30 AM on [Month] [Day]. The blunt force injuries on the deceased were non-fatal, the clothing damage was caused by external tearing, and the fibers extracted from the scene are consistent with those extracted from the autopsy, most likely belonging to the suspect." He continued, "Now, we will adjust our investigative approach and focus our work on the following aspects:"

"First, we arranged for team members to conduct a comprehensive investigation of agricultural supply stores and pesticide stores throughout the city, with a focus on those who had purchased methamidophos 1 to 7 days before the incident. We recorded in detail the names, identities, contact information, and quantities purchased by the purchasers, especially men between the ages of 30 and 35. We verified their identities and activity trajectories one by one, investigated their connection with the deceased, and identified key suspects."

"Second, continue to expand the scope of monitoring and investigation, focusing on the surveillance cameras along Jianshe Road, around construction site fences, and around agricultural supply stores 1 to 2 days before the incident, to find suspicious persons who purchased methamidophos, as well as the activity trajectories of the deceased and the criminal suspect, especially the white van, and be sure to find relevant clues about it."

"Third, continue to visit the public and expand the scope of visits, focusing on visiting the owners and staff of agricultural supply stores and pesticide stores around the construction site, asking them if they have seen the deceased recently, or if they have seen any suspicious persons buying methamidophos. At the same time, visit areas where the deceased may have been, such as internet cafes, hotels, and rental houses, to look for clues that can prove the identity of the deceased."

"Fourth, the technical department will expedite the examination and comparison of fingerprints, fibers, and other trace evidence collected at the scene. The fingerprints collected at the scene will be compared with the fingerprints of the people who purchased methamidophos, and the fiber samples will be compared with the clothing fibers of the suspects, in an effort to identify the criminal suspects."

"Fifth, wait for the DNA test results. Once the identity of the deceased is confirmed, immediately begin an investigation into the deceased's social relationships, work experience, and interpersonal interactions to find people who have conflicts or disputes with the deceased. These people are very likely to be the criminal suspects."

"Sixth, arrange team members to re-verify all personnel entering and leaving the subway construction site, especially those who entered the site before and after the incident. Check their identities and activity trajectories one by one, eliminate the suspicion of irrelevant personnel, and focus on investigating those who could obtain methamidophos and had contact with the deceased."

"Comrades, the case investigation has entered a crucial stage. Although the victim's identity has not yet been confirmed and the suspect has not been identified, we have obtained the time of death, the cause of death, and some important clues. As long as we go all out, expand the scope of our investigation, and do every task meticulously, we will definitely be able to identify the suspect, uncover the truth of the case, and bring justice to the deceased." Lu Chuan's tone was full of confidence. "Now, everyone, get to work immediately, according to your assigned tasks, and report any leads immediately!"

"Understood, Captain Lu!" all the team members responded in unison, and then immediately began the follow-up investigation work according to Lu Chuan's plan. The team members were all in high spirits. Although they had been working continuously for more than ten hours and were exhausted, they did not slack off in the slightest. They had only one goal in mind: to identify the suspect as soon as possible, find out the truth of the case, and clear the name of the deceased.

In the provincial criminal investigation team's laboratory, Zhang Kai and Xiao Lin were still busy. They awaited the final DNA test results while further examining the fiber samples to analyze their specific origin. Zhang Kai, holding a microscope, carefully observed the fiber morphology and said to Xiao Lin, "Xiao Lin, look, these black cotton fibers are rather coarse, probably the material of ordinary work clothes. These brown synthetic fibers are fine-textured, likely the material of an overcoat or trousers. Based on the scene investigation, the suspect was likely wearing clothing containing both types of fibers. We can use the fiber material and characteristics to trace the relevant clothing sales channels and find clues about the suspect."

"Understood, Teacher Zhang! I'll immediately organize the characteristics of the fibers, contact relevant clothing manufacturers and sales channels, and investigate clothing containing these fibers in order to find useful clues," Xiao Lin said, and immediately took action, organizing the relevant characteristics of the fibers, contacting clothing manufacturers and sales channels, and launching the investigation.

Time ticked by. At 11:00 AM, 12:00 PM, 1:00 PM, and 2:00 PM, the DNA testing continued intensely. Zhang Kai and Xiao Lin grew increasingly anxious, hoping to quickly confirm the deceased's identity through DNA comparison and provide more clues for solving the case. During this time, they repeatedly inquired with the lab staff about the progress of the DNA testing. The staff consistently assured them that they were speeding up the comparison process and would obtain results as soon as possible.

At 3 p.m. sharp, the laboratory staff finally completed the DNA testing and comparison. They immediately found Zhang Kai and Xiao Lin and reported: "Forensic Doctor Zhang, the DNA testing and comparison has been completed. We have compared the deceased's DNA sample with the city's missing persons database, and found no matching missing persons information. In other words, we still cannot confirm the deceased's identity at present."

Upon hearing this news, Zhang Kai and Xiao Lin both showed a hint of disappointment. Xiao Lin couldn't help but say, "How could this be? We've already compared the missing persons information across the city, and there's no match. What was the deceased's identity? Who was he?"

Zhang Kai's expression also turned serious. (End of Chapter)