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

Fifty meters downstream, the two found more clues in an open area. Yang Sen's probe struck a soft object in the soil. He carefully dug away the dirt, revealing a piece of black cloth. "It's canvas!" Yang Lin exclaimed excitedly, "The same material as the canvas bag used to wrap the body!"

The piece of canvas was about the size of a palm, with obvious tear marks on the edges, and covered with a lot of silt and algae. "It should be a fragment that fell off when the bag was snagged by a branch by the ditch while wrapping the body." Yang Sen put the canvas fragment into the evidence bag. "Look, there is a white thread on the fragment. It's not the canvas's own thread. It looks like it was used for later repairs. It matches the repair thread on the bag, further confirming that it's from the same bag."

Next to the canvas fragments, Yang Lin also found half a cigarette butt. "It's a Liqun brand, the same as the cigarette butt we found on the east side of the body before!" He picked up the cigarette butt with special tweezers. "There are teeth marks on the filter, and comparing them with the teeth marks on the previous cigarette butts, we can confirm that it was left by the same person. The cigarette butt is still very wet, which means it was not discarded for long. It should be left by the suspect when he disposed of the body."

“There’s definitely the suspect’s saliva on the cigarette butt. We can get a DNA sample when we get back, and maybe we’ll make a big breakthrough!” Yang Sen said excitedly. Yang Lin, however, calmly shook his head: “Don’t be too happy yet. The cigarette butt has been buried in the damp soil for so long, the DNA may have been damaged. But we still have to do our best to test it. Maybe we can extract some DNA profile.”

The two continued their investigation downstream until they reached the intersection connecting to the main road, where they stopped. By then, it was completely dark, and the beams of their searchlights shone brightly in the darkness. Yang Lin took out his notebook and meticulously reviewed the newly discovered clues: "Upstream, we found fragments of a wrench, a shoe print matching size 43, and red brick fragments; downstream, we found coarse brown fibers, fragments of canvas, and half a cigarette butt. While these clues supplemented the suspect's movements and possible items, we still couldn't find anything that could identify the deceased—no identification, no jewelry, not even a label to identify the clothing brand."

“Yes,” Yang Sen leaned against a tree trunk by the roadside, wiping the sweat from his forehead. “The deceased was wrapped up too tightly. There was nothing in the bag except the body. The suspect must have deliberately cleaned it up to prevent us from identifying the deceased through the items. The traces we have found can only narrow down the suspects, but we can’t determine who the deceased is. Without the identity of the deceased, it will be very difficult to carry out the subsequent investigation.”

Yang Lin flipped through the notes in his notebook, his brow furrowing slightly. "However, there are a few things we can be sure of: First, the suspect is indeed connected to the construction or demolition industry. Wrench fragments, red brick chips, and nylon safety ropes are all common items found on construction sites. Second, the suspect is very familiar with the area around the drainage ditch, knows where there are blind spots in surveillance cameras, where it's suitable to dump the body, and even knows that abandoned drainage outlets upstream can hide his tracks. He has a strong sense of counter-surveillance. Third, the suspect smokes, the brand is Liqun, has a habit of chewing cigarette butts, is 175-180 cm tall, weighs 70-75 kg, and wears size 43 mesh sneakers. Although these characteristics are clear, without the victim's identity as a breakthrough, the investigation will still be very difficult."

"Do you think the suspect might be a worker at the demolition site?" Yang Sen suddenly asked. "There are nylon safety ropes, red bricks, and tools like wrenches at the construction site, and the workers are definitely familiar with the surrounding environment, which matches the characteristics we currently have."

Yang Lin nodded: "That's possible, but we can't rule out people who have business dealings with the construction site, such as building material suppliers or waste recyclers. When we get back, we need to have Wang Shuai and the others conduct a thorough investigation of the workers at the demolition site, especially those who match the height and weight characteristics and have recently exhibited unusual behavior, such as suddenly taking leave, being depressed, or wearing size 43 mesh sneakers."

The two packed up their investigation tools and prepared to return to the Criminal Investigation Division. Halfway there, Yang Sen suddenly remembered something and turned back to the downstream location where they had found the canvas fragments. He shone his investigation light on the ground again: "Look, there's a small amount of white powder in the soil next to the canvas fragments. We didn't notice it before." He used a cotton swab to collect a small amount of powder and put it into a sample bottle. "This powder looks like some kind of paint. The color is different from the brown marks we saw on the wrench fragments. Let's test it together when we get back and see if we can find the source."

When the two returned to the Criminal Investigation Division, Lu Chuan was discussing the surveillance footage with Wang Shuai. After Yang Lin and Yang Sen reported on the newly discovered evidence and investigation results, Lu Chuan took the evidence bag they handed him. Looking at the wrench fragments, canvas fragments, cigarette butts, and white powder inside, he frowned slightly: "There are more clues than before, but the core issue remains unresolved—the victim's identity is still unknown. However, your findings are not without value; at least they further confirm the suspect's connection to the construction industry, providing a clearer direction for subsequent investigations."

"When will we get the test results for these pieces of evidence?" Yang Sen asked anxiously. Lu Chuan looked in the direction of the technical department: "I've already spoken to them. Prioritize testing these pieces of evidence, especially the DNA from the cigarette butt, the oil content from the wrench fragments, the nature of the white powder, and the stitching from the canvas fragments. We'll try to get the results by tomorrow morning. If we can extract the suspect's DNA from the cigarette butt, even if we can't identify the deceased for the time being, it will narrow down the scope of our investigation."

Yang Lin and Yang Sen nodded and carefully handed the evidence to their colleagues in the technical department. As they left the technical department, night had fallen, but the Criminal Investigation Division's office building was still brightly lit. Standing in the corridor, looking out at the night sky, the two knew that although the expanded investigation had uncovered many traces and clues, there was still a long way to go before identifying the victim and the suspect. However, they were not discouraged—every discovery was a step closer to the truth, and as long as they persisted with meticulous investigation, they would eventually unveil the mystery of this decomposing corpse case in the drainage ditch.

"Hopefully the technical department will bring good news tomorrow," Yang Sen rubbed his sore shoulders. "Especially the DNA from the cigarette butt. If we can extract it, the case will take a turn for the better."

Yang Lin patted him on the shoulder: "There will be good news. Let's go back and review all the traces again, see if there are any missing connections. For example, if the oil stains on the wrench fragments match the machine oil from the construction site, it will further narrow down the suspects; if the white powder is paint, the suspect might be a decorator or painter, and these could be key breakthroughs." (End of Chapter)