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

"Captain Zhang, this is not a solution." Team member Xiao Li was chewing noodles. "The villagers either said they didn't see anything, or the information they provided was ambiguous."

Zhang Hui picked up a bowl of noodles with chopsticks and thought for a moment: "Let's go to the neighboring Yanglin Village this afternoon and expand the scope of the inquiry. Since the murderer chose to dump the body in the cornfield, he might be familiar with the surrounding environment and may be able to find a breakthrough in other villages."

The afternoon sun was a bit scorching, and the cicadas were chirping. In the grain drying field of Yanglin Village, several old men were lying on bamboo mats to enjoy the cool. Zhang Hui walked over and squatted beside an old man who was fanning himself with a cattail leaf fan: "Uncle, I want to ask you something. A body was found in the cornfield of Qinggang Village. Have you heard about it?"

The old man stopped fanning himself and said, "I heard that things are not peaceful these days."

"Have you heard of any outsiders wandering around recently? Or has anyone in the village suddenly gained some unidentified valuables?"

The old man smacked his lips and said, "I haven't seen any outsiders, but as for the property..." He suddenly lowered his voice and said, "A few days ago, Wang Ermao, a second-rate guy in the village, bought a new mobile phone, the latest model. He can't even afford a meal, so where did he get the money? But I just said it casually, don't get him into trouble."

Zhang Hui's eyes lit up and he wrote down the clue: "Uncle, don't worry, we are just checking for clues. Do you know anything else about Wang Ermao?"

"This kid has no parents since he was young. He grew up with his grandmother. After his grandmother passed away, he has been living a carefree life." The old man sighed, "Recently, I rarely see him wandering around the village. I don't know where he went."

After bidding farewell to the old man, Zhang Hui immediately arranged for his team to check Wang Ermao's whereabouts. However, after investigation, it was found that Wang Ermao bought his new phone at a second-hand market in the county, and the transaction records and surveillance confirmed this. This seemingly valuable clue eventually became useless.

As the sun sets, Zhang Hui and his team members drag their heavy steps back to the police car. After a day of interviews, they were so thirsty and their legs felt heavy as if they were filled with lead, but they still hadn't found any valuable clues. But Zhang Hui knew that criminal investigation work was like this, looking for hope in countless disappointments, and never giving up even if there was only a glimmer of possibility.

The incandescent lights in the conference room were buzzing, and Lu Chuan erased the clue map on the whiteboard for the third time. The red and blue marker marks were layered like a knot, and the live images of the cornfield played on the projection screen in a loop, looking even more eerie in the cold light. The electronic clock on the wall showed 2:17 in the morning. The participants' ties were crooked, their shirts were wrinkled like pickles, and the ashtrays were piled with cigarette butts that were almost overflowing.

"From matching missing persons, hospital records to visiting the surrounding areas, all conventional directions have hit a wall." Lu Chuan poked a laser pen at the close-up of the deceased's sole on the screen. After magnifying it twenty times, every groove of the diamond grid pattern on the rubber sole was clearly visible. "Now, our only breakthrough is this pair of shoes." Wang Shuai opened a badly worn notebook, with a few wrinkled visit records sandwiched between the pages: "Based on the depth of the shoe prints and the wear characteristics, the deceased weighed about 75 kilograms, and the fulcrum of his right foot was on the inside, indicating a long-term walking habit. But this diamond grid pattern is so special. We ran all over the city's labor protection supplies stores, and even wholesalers had never seen the same one." He projected the photos on his mobile phone, and the shelves of more than stores quickly switched on the screen, all with striped or wavy soles.

Zhang Hui pinched the back of his aching neck and added: "Could it be a niche brand or a custom model? I contacted all the shoe factories in the province, and there was no matching record in the database. But a factory technician mentioned that this pattern design is more like the style of labor protection shoes exported in the 1990s. Maybe it's old inventory."

Forensic doctor Zhang Kai suddenly raised his hand, and the fluorescent mark on the autopsy report flickered under the light: "I extracted trace substances from the cracks in the soles of the deceased's shoes. In addition to the soil from the cornfield, there was also a black tar-like component. After gas chromatography analysis, the match with the asphalt component was 87%, but the benzopyrene content detected was abnormally high - this is a characteristic of industrial-grade high-temperature asphalt." He pulled up a comparison chart, "Combined with the deceased's history of liver cirrhosis, it is very likely that he was exposed to this type of substance for a long time before his death."

Yang Sen turned the wheel of the 3D model, and the virtual crime scene slowly rotated on the screen: "We traced the tractor marks on the route where the body was dumped to an agricultural machinery repair shop in the neighboring county. But the owner said that too many vehicles had changed to such tires in the past three months, and they couldn't locate it at all. But there is a detail worth noting -" He zoomed in on the shoe prints on the edge of the field, "At the starting point of the drag mark, there are small metal fragments next to the shoe prints. Spectral analysis shows that it is an iron-aluminum alloy, which is commonly found on scaffoldings in construction sites."

The conference room fell silent, with only the roar of the air conditioner tearing the air. Lu Chuan suddenly loosened his tie and drew three overlapping circles on the whiteboard: "Put all the information together: 1990s-style safety shoes, history of exposure to industrial-grade asphalt, and metal residues from construction sites. The identity of the deceased gradually became clear - he was most likely a migrant worker engaged in road construction or building maintenance."

He pointed the laser pointer at the traffic routes on the map: "Focus on checking all road renovation and bridge reinforcement projects in the city in the past five years. Especially for projects using high-temperature asphalt, retrieve the construction party's employment records and compare the workers' shoe sizes and age ranges. At the same time, expand the scope of shoe print comparison to the labor insurance market in the three surrounding provinces. Even if it is inventory from ten years ago, the manufacturer must be found!"

In the next two weeks, the entire criminal investigation team was caught up in a frantic investigation. Zhang Hui and his team spent time in the Urban Construction Archives, searching for clues in tons of engineering files; Wang Shuai's team traveled to labor protection warehouses in surrounding counties and cities, searching for similar patterns in piles of old shoes; Yang Sen classified the city's surveillance videos by road construction project, screening for suspicious persons frame by frame.

However, hopes were raised and dashed again and again. There were no missing persons matching the description in the construction records. The old shoes in the labor protection market occasionally had diamond patterns, but the details did not match. None of the tens of thousands of workers in the surveillance footage wore the same shoes. When the 137th test report showed "no match", Xiao Lin pounded the table in frustration: "These shoes look like they came from Mars! Why can't we find a second pair in the world?"

Lu Chuan stood in front of the whiteboard, looking at the "high-temperature asphalt" and "metal debris" circled in red pen, and suddenly remembered a sentence in Zhang Kai's report - "benzopyrene content is abnormally high." He picked up the phone and called the physical evidence department. (End of this chapter)