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

Chapter 1303 Trace Analysis

Xiao Sun responded and picked up a high-powered searchlight: "Okay, I'll focus on checking the ground and tree trunks in the woods to see if there are any climbing marks or tool marks left by the suspect; you should pay more attention to the soil on the east side, the previous construction may not have affected that area, you might be able to find complete tire tracks or footprints there."

The two split up. Xiao Yang, carrying the electrostatic precipitator, slowly walked along the eastern edge of the lawn. The weeds on the eastern side were denser and the soil more compact than around the planting pits, showing no signs of being disturbed by construction. He crouched down, parted the weeds, and the beam of his powerful surveying light swept across the ground, suddenly stopping at a light brown area of ​​soil—the weeds here showed signs of being trampled, and two parallel marks were faintly visible on the soil surface.

"Xiao Sun, come take a look! We found what looks like tire marks on the edge of the lawn on the east side!" Xiao Yang shouted into the walkie-talkie, his finger lightly brushing across the surface of the soil. "The marks are very faint, but you can see two parallel indentations, about 8 centimeters wide and 40 centimeters apart. They don't look like tire marks from a sedan or SUV; they look more like those from a small vehicle."

Xiao Sun arrived quickly, squatted down, and carefully measured with a tire imprint measuring instrument: "The width is 8.1 centimeters, and the spacing is 40.2 centimeters. These parameters are more consistent with the tire size of electric tricycles or motorcycles! Look at the edge of the imprint; there are fine grooves, which should be left by the tire tread, but they are covered by weeds and mud, so the details are not very clear. We'll fix it with plaster powder and take a sample back for comparison."

The two carefully sprinkled plaster powder onto the tire tracks. While waiting for the plaster to solidify, Xiao Yang used an electrostatic adsorbent to attract the material around the tracks. Suddenly, the indicator light on the adsorbent lit up. He carefully removed the adsorbed material and placed it in the evidence bag: "Found something! We found several light blue fibers, about 3 millimeters long. The texture looks like synthetic fiber. They may have come off the suspect's clothing or the vehicle seat."

Xiao Sun leaned over and looked at the fibers in the evidence bag: "Light blue synthetic fiber. This material is commonly found in work pants, sports jackets, and electric tricycle seat covers. If this fiber is related to tire marks, it might narrow down the scope of the investigation—for example, people who frequently ride electric tricycles or motorcycles and wear clothing made of synthetic fibers."

The plaster had hardened and thickened. The two carefully extracted the tire track sample, marked its location, and continued their investigation deeper to the east. After walking about 50 meters, Xiao Yang found new traces under a large tree: "There's a blurry footprint here!"

Xiao Sun immediately stepped forward, focusing the beam of his powerful forensic light on the ground: "The footprints are very shallow, the shoe size is about 42, the sole pattern is blurry, only the general wavy pattern can be seen, it should be left by sneakers. However, the footprints are covered by leaves and soil, so it is impossible to extract complete features, and it is not possible to determine whether they are related to the case for the time being."

"Mark this down first, and we'll analyze it together with other traces when we get back." Xiao Yang took out a marker and made a mark on the tree trunk. "Keep checking ahead and see if there are any other tire tracks or other debris."

The two continued their investigation of the eastern area and discovered two more blurry tire tracks, consistent in size with the previously found ones, approximately 8 centimeters wide and 40 centimeters apart, suggesting they were left by the same vehicle. "These tire tracks are distributed in a straight line, extending from the eastern edge of the lawn towards the woods, indicating that the suspect likely rode an electric tricycle or motorcycle into the lawn from the eastern path and then headed towards the planting pit," Xiao Yang preliminarily deduced, observing the distribution of the tracks.

Meanwhile, Xiao Sun made a discovery during his investigation in the woods to the west. He shouted into the walkie-talkie, "Xiao Yang, I found a tool mark in the woods to the west!"

Xiao Yang rushed over immediately and saw a scratch about 10 centimeters long and 0.5 centimeters deep on the trunk of a large tree. The edges of the scratch were neat, like the edge of a shovel or hoe. "This scratch is very new. The damaged part of the bark hasn't completely oxidized yet. It should have been left within the last six months." Xiao Sun touched the scratch with his finger. "The angle and depth of the scratch are consistent with the marks left when digging with a shovel and accidentally hitting the trunk. It might have been caused by the suspect moving tools when burying the body."

Xiao Yang took out his camera and photographed the scratches from different angles: "Very likely! Look around the scratches for any fibers or hairs."

Xiao Sun used an electrostatic adsorbent to pick up fibers around the scratch and found a few more: "Yes! This time it's dark gray cotton fiber, about 2 millimeters long. It's different from the light blue synthetic fiber we found before, so it may come from a different item."

“Two different types of fibers, tire marks from an electric tricycle or motorcycle, and shovel scratches on the tree trunk—these clues should connect.” Xiao Yang put away his camera, sat on the grass, and worked with Xiao Sun to analyze the case. “The suspect probably rode an electric tricycle or motorcycle from the east or west side of the park into the unused lawn, carrying shovels and other digging tools. After reaching the vicinity of the planting pit, he used the shovel to dig the pit and bury the body. In the process, he accidentally left scratches on the tree trunk, and fibers from clothing or vehicle seats also fell to the scene. After burying the body, he rode away along the same route, leaving these tire marks.”

Xiao Sun nodded and added, "This deduction is reasonable, but there are still a few questions. First, why did the suspect choose to transport the body using an electric tricycle or motorcycle? These vehicles have limited carrying capacity and are relatively obvious targets, unlike cars which are more discreet. Second, what is the source of the two types of fibers found at the scene? Are they the suspect's clothing or items used to wrap the body? Third, the tire tracks only extend deep into the lawn and do not approach the planting pit, indicating that the suspect may have parked some distance away from the planting pit and then carried the body to the edge of the pit on foot. Why didn't they drive directly to the vicinity of the planting pit?"

“These questions need to be answered by further analysis of the traces.” Xiao Yang stood up and patted the dirt off his clothes. “The electric tricycle or motorcycle is a clear target, which may indicate that the suspect did not have a car, or felt that the narrow roads around the park were inconvenient for a car to enter; the two types of fibers may have come from the suspect’s clothing and the sheet used to wrap the body; as for not driving the vehicle near the planting pit, it may be because they were afraid that the vehicle would be too noisy, or they were worried that the wheels would sink into the soft soil and leave more obvious traces.”

The two continued their investigation in the woods to the west and discovered another blurry tire mark, the same size as the one found to the east, further confirming their hypothesis that "the same vehicle entered and exited." In addition, Xiao Sun found a small, irregularly shaped, black, and hard piece of plastic under a bush; its purpose was not yet determined, but it was also collected as evidence.