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

"Third, send the physical evidence for testing. Yang Sen, you immediately lead the technical staff to transport all the physical evidence collected at the scene, including the incomplete plaster model of the footprint, dark clothing fibers, dark blue plastic fragments, soil samples, and trace residues on the tree branches, back to the branch's technical department for testing and analysis. Focus on testing the material and source of the plastic fragments, the material and type of the clothing fibers, and the pattern characteristics of the footprints, and strive to obtain the test results as soon as possible to provide clues for solving the case."

"Fourth, conduct door-to-door investigations. Arrange a team of police officers to immediately conduct a comprehensive, grid-like investigation of Zhangjiagou and the surrounding three villages of Lijiagou, Wangjia'ao, and Zhaojiapo, asking each household without missing a single one. The investigation should focus on whether any outsiders have entered the village in the past month, whether any unfamiliar vehicles have entered the mountains, whether anyone has gone missing, whether anyone has suddenly left the village recently, whether anyone has quarreled, had grudges, or had debt disputes, or whether anyone has made any threats or statements of revenge."

“When conducting door-to-door visits and investigations, pay attention to your approach and tone. Be calm and avoid causing panic among the villagers, and don’t overlook any details. Tell the villagers the characteristics of the stranger described by Zhang Baolu and ask them to help recall if anyone has seen this stranger, knows where he/she is, or has noticed anything suspicious.”

"Fifth, conduct a surveillance check. Yang Sen, arrange another group of police officers to check all the surveillance cameras along all the small roads and intersections leading into the mountains, as well as the surrounding town roads, village shops, and farmers' doorsteps. Although there is a high probability that there are no surveillance cameras in the mountains, do not give up any hope. Even the surveillance cameras installed by farmers themselves or the surveillance cameras of small shops should be retrieved and the footage from the past seven days should be checked. The focus should be on finding the stranger described by Zhang Baolu, the black plastic bag, and suspicious vehicles, especially motorcycles, tricycles, and off-road vehicles that can drive into the mountains."

"Sixth, missing persons comparison. Contact the command center and coordinate with all police stations in the city to retrieve all information on recent missing persons, especially male missing persons, and compare them one by one, focusing on the age, height, build, clothing, time of disappearance, and location of disappearance of the missing persons. Combine this with the situation at the scene to rule out the identity of the deceased and narrow down the scope of the investigation."

"Seventh, supplementary interviews with witnesses. Arrange for someone to conduct several more supplementary interviews with Zhang Baolu, especially regarding the details of the stranger. Ask him to recall carefully, such as the man's walking posture, the range of his arm swings, the way he carried the bag, and the specific time and weather conditions when he saw the man that day. No detail should be overlooked. At the same time, we should also interview other villagers who frequently go up the mountain to graze livestock and gather mountain products to see if they have seen a stranger recently or noticed anything unusual in the mountains. Expand the scope of witnesses and try to obtain more clues."

"Eighth, body transfer. Yang Sen, you coordinate the detachment's transport vehicles, arrange professional personnel, and ensure proper protective measures are in place. Carefully transfer the body out of the cave and back to the detachment's forensic identification center, where Zhang Kai will be responsible for the autopsy. During the transfer, maintain the body's original state; do not move or touch any part of the body to avoid damaging any trace evidence that may remain. At the same time, maintain confidentiality to avoid causing panic or unnecessary discussion among the villagers."

"Ninth, information gathering. Everyone must report their work progress to me promptly at 5 PM every day. Whether it's visiting and investigating, monitoring and investigating, examining physical evidence, or comparing missing persons, any discovery, even a trivial detail, must be reported immediately. There must be no concealment or delay. I will gather all the information every day, adjust the direction of the investigation, and ensure that the case investigation proceeds in an orderly manner."

"Tenth, safety precautions. All personnel involved in on-site investigations and interviews must take good care of their own safety, especially those entering cave dwellings for investigation. They must wear gas masks, gloves, and shoe covers to avoid contact with putrid liquids and insects to prevent infection. Personnel conducting interviews and investigations should pay attention to safety when walking in the mountains, beware of wild animals and traps, and ensure their own safety."

"Did everyone hear me clearly?" Lu Chuan's voice, transmitted through the walkie-talkie, reached the ears of every police officer involved in the case investigation. His tone was firm and carried an unquestionable authority.

"Understood, Captain Lu!" all the police officers responded in unison, their voices loud and clear, full of fighting spirit. Although the case had few clues and was extremely difficult, they did not back down in the slightest. Everyone was determined to catch the murderer as soon as possible and bring justice to the victim.

"Alright, now, everyone, get to your posts and get moving!"

At Lu Chuan's command, all the police officers immediately sprang into action, splitting up to carry out their respective tasks according to the plan. Yang Lin led the investigation team to remain in the mountains to conduct a second investigation of the scene and surrounding area; Yang Sen coordinated the transport vehicles to prepare for the transfer of the body; the interview and investigation team, the surveillance investigation team, and the missing persons comparison team also set off to engage in the intense investigation.

Lu Chuan didn't leave Zhangjiagou. He stayed at the village entrance, coordinating various tasks while awaiting news of the body's transfer. Standing on the dirt road at the village entrance, gazing at the rolling mountains, his brow furrowed, he repeatedly recalled Zhang Baolu's testimony and the on-site investigation reports from Yang Lin and Yang Sen, trying to find more breakthroughs. The strange man, the black plastic bag, the dark blue plastic fragments, the incomplete footprints—these clues swirled in his mind, connecting vague images, but failing to form a complete direction for the investigation.

He knew that the most crucial task at present was to quickly identify the deceased, locate the primary crime scene, and identify the suspect. All of this depended on forensic autopsies and the analysis of physical evidence. Only through autopsies, determining the deceased's time of death, cause of death, age, height, weight, and other individual characteristics, could the pool of missing persons be narrowed down and the deceased's identity confirmed. Only through the examination of physical evidence, identifying the source of plastic fragments, clothing fibers, and footprints, could the suspect's trail be pinpointed.

About an hour later, Yang Sen called, his voice calm: "Team Leader Lu, the transport vehicle has arrived in the mountains. The investigators have taken protective measures and are carefully transferring the body out of the cave. The process is going smoothly; the body has not been damaged in its original state, and no physical evidence has been missed. We expect to be able to transport the body back to the branch's forensic identification center in half an hour." (End of Chapter)