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

Yang Sen's gaze was fixed on the soil surrounding the pit, moving slowly and meticulously, leaving no corner unchecked. Initially, the soil around the pit was somewhat messy due to Qin Xueli's disturbance, and some of Qin Xueli's footprints were visible. Yang Sen carefully examined them, eliminating Qin Xueli's footprints one by one, focusing on those suspicious footprints that didn't belong to Qin Xueli. After more than ten minutes of meticulous investigation, Yang Sen finally discovered a clear footprint on the north side of the pit, about 30 centimeters from the edge.

The footprint was a shoe print, imprinted in the soft soil, its outline clear, showing the tread pattern and other details of the sole. Yang Sen was overjoyed. He quickly grabbed his flashlight, adjusted the angle, and carefully shone it on the footprint. At the same time, he gestured for Yang Lin to come over and examine it together. "Yang Lin, come quick! We found a suspicious footprint here. The outline is very clear; it should be left by the murderer," Yang Sen's voice carried a hint of barely perceptible excitement, but his tone remained calm and unwavering.

Upon hearing Yang Sen's call, Yang Lin quickly put down the tweezers and brush he was holding, hurried over to Yang Sen's side, squatted down, and carefully examined the suspicious footprint with a magnifying glass. "Indeed, this footprint is very suspicious," Yang Lin said slowly after observing it carefully for a moment. "Judging from the size and outline of the footprint, it should be a male shoe print, about size 42. The sole is rubber, with obvious horizontal ridges. Between the ridges, there are still some small bits of soil and weed fragments. Moreover, the depth of the footprint is about 2 centimeters. Combined with the softness of the soil, we can deduce that the person who left this footprint was about 175-178 centimeters tall, of medium build, weighed about 65-70 kilograms, and was about 25-40 years old."

“Furthermore, this footprint is intact and has a clear outline, indicating that the person who left it did not deliberately clean up the scene after burying the body, or did not clean it thoroughly enough,” Yang Lin continued, carefully extracting the footprint with trace extraction paper as he spoke. “Moreover, judging from the direction of the footprint, it is pointing towards the pit, indicating that the person who left it was walking towards the pit, and is most likely one of the murderers who buried the body. We will first photograph this footprint for evidence, fix it with plaster, extract samples, and then continue the investigation to see if we can find any other footprints.”

Yang Sen nodded, and then the two divided the work. Yang Sen was responsible for taking photos of the suspicious footprint from different angles to ensure that every detail of the footprint was clearly recorded; Yang Lin was responsible for mixing the plaster, carefully applying it to the footprint to fix it in place, and extracting a plaster sample from the footprint. Throughout the entire process, the two were very meticulous and cautious, moving gently, for fear of accidentally damaging the footprint and affecting subsequent comparison and analysis.

After securing and extracting the suspicious footprint, Yang Lin and Yang Sen continued their footprint investigation around the pit, expanding the search area from the north side of the pit to the south, east, and west sides, carefully examining every inch of soil and searching for other suspicious footprints. After more than half an hour of meticulous investigation, they discovered another suspicious footprint on the west side of the pit, about 50 centimeters from the edge.

This suspicious footprint is very similar to the one previously discovered. It's also a male shoe print, around size 42, with a rubber sole and horizontal ridges. The footprint is about 1.8 centimeters deep, slightly shallower than the first footprint, suggesting it was likely left by the same person. However, it could also have been left by another person—after all, disposing of a body usually involves multiple perpetrators, or the killer might have moved around the scene leaving multiple footprints. Yang Lin and Yang Sen followed standard procedures, photographing the footprint, fixing it in a plaster cast, and extracting a sample. They also carefully observed the details of the footprint and recorded relevant information for later comparative analysis.

While examining the footprints, Yang Lin didn't neglect the examination of minute physical evidence. He squatted around the pit, tweezers and a brush in hand, carefully combing through the weeds and pebbles in the soil, his gaze focused, not missing a single tiny fiber, hair, or other suspicious piece of evidence. In the soil around the pit, besides a large amount of corn stalk debris and weeds, there were some fine fibers of various colors—black, gray, and white—and a small wisp of brown hair, which looked like human hair, but could also be animal hair, requiring further testing for confirmation.

Yang Lin carefully used tweezers to pick up the tiny fibers one by one, placing them into pre-prepared sealed bags, labeling them with the extraction location, time, and person. He was especially cautious with the strand of brown hair, carefully cleaning the dirt around it with a brush before gently picking it up with tweezers, placing it in a sealed bag, and labeling it separately to avoid confusion with other fibers. "These fibers look quite unusual," Yang Lin said slowly, holding a sealed bag containing black fibers up to the sunlight and examining it closely. "These black fibers look like they're made of synthetic materials, possibly from the killer's clothing; the gray and white fibers look like cotton, possibly from the victim's clothing, or possibly from the killer's; and this strand of brown hair needs further testing to confirm whether it's human or animal hair. If it's human hair, it might provide us with information about the victim or the killer."

While examining the footprints, Yang Sen responded, "That's right. These tiny fibers and hairs, though seemingly insignificant, could very well be key clues, especially the black fibers made of synthetic material. They're most likely from the killer's clothing. If we can find out the source of these fibers, we can narrow down the search and find relevant clues about the suspect. Let's continue our investigation and see if we can find more fibers, hairs, or other suspicious minute evidence."

The two then continued their investigation. Yang Lin was responsible for collecting and recording minute physical evidence, while Yang Sen was responsible for examining and collecting footprints. Their division of labor was clear, and they cooperated seamlessly. After more than an hour of meticulous investigation, they extracted more than a dozen fibers of different colors around the pit, including black, gray, white, brown, and one red fiber. The fibers varied in material, including synthetic fibers, cotton, and wool. (End of Chapter)