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

More and more anglers gathered outside the cordon, their chatter rising like a tide. Lu Chuan gave orders into the walkie-talkie: "Immediately retrieve surveillance footage from surrounding roads and investigate suspicious vehicles from the night of June 14th; contact the hydrological station to obtain water flow data for the past three days; visit nearby villages to search for missing persons, focusing on men between 178-183 cm tall wearing black jackets." The morning mist gradually dissipated, and sunlight shone on the murky river surface, creating a blinding light, as if to completely illuminate the evil hidden beneath the water.

Yang Lin and Yang Sen's investigation logs already filled two pages, detailing everything from shoe print characteristics and fiber composition to tire tracks and cigarette butt brands—every clue pointing to the lurking killer. At this moment, the secret beneath the surface remains unsolved, but as the investigation deepens, the truth will eventually be exposed to the light of day, like a body pulled ashore.

When Lu Chuan's instructions came through the walkie-talkie, Yang Lin was squatting by the water photographing the newly discovered set of keys. "Expand the search area to 200 meters upstream and downstream of the riverbank, focusing on the wooded areas and abandoned docks." Amidst the static and the discussions outside the cordon, Yang Lin looked up at the gradually dissipating morning mist, carefully placed the keys into the evidence bag, and said, "Roger that, we'll start upstream."

Yang Sen followed behind, carrying his investigation bag, the cable of his footprint light leaving shallow marks in the mud. "This size 44 shoe print extends from the riverbank to the water's edge and then stops," he said, measuring the last complete shoe print with a ruler. "The stride length shortened from 78 centimeters to 75 centimeters, indicating that the suspect slowed down after reaching the water's edge." The reeds upstream were denser, and the flapping sounds of water birds could be heard from the knee-high grass.

“Look at these fallen reeds,” Yang Lin said, parting the waist-high grass blades. The beam of his survey lamp shone on a patch of messy grass. “The stems broke in the same direction, all falling from northwest to southeast, which is consistent with the stress characteristics of dragging a heavy object.” He squatted down and used tweezers to pick up a root-covered fiber. “Black polyester, consistent with the preliminary judgment of the body’s clothing, 8 centimeters long, with obvious stretch marks.”

Yang Sen's footprint light made a new discovery in the mud: a series of blurry footprints superimposed on Li Baochang's rubber shoe print. "It's still size 44, but the wear on the sole pattern is different," he compared the two patterns. "The forefoot pattern of this shoe print is deeper, so it might be another pair of the same style of shoes, or the suspect's soles got mud on them, causing the pattern to change." The footprints disappeared under a willow tree ten meters away, where there were fresh signs of soil being disturbed at the base of the tree.

“The suspect may have lingered here,” Yang Lin said, brushing away the loose soil to reveal a shallow pit about 30 centimeters in diameter. “There were traces of black cloth rubbing against the bottom of the pit, and dark red stains on the edges. The alcohol test came back positive—suspected bloodstains.” He found a half-smoked cigarette butt near the pit, the same Yuxi brand as the one he had found before, with more concentrated saliva stains on the filter. “The smoking was deeper than before, indicating that the suspect may have hesitated or waited here.”

The two walked up the riverbank when Yang Sen suddenly pointed to a shallow area on the shore: "There's an unusual water stain here, shaped like a rectangle." He tested it with pH paper. "The pH is 7.5, and the sand content is higher than the surrounding water, so it's possible that a heavy object was placed there." There were faint tire marks at the edge of the water stain, which matched the tire treads of the car they had found earlier. "The tire was 18 centimeters wide, and there were bits of aquatic plants embedded in the tread pattern, so it should have been left by the same car."

“The murderer likely drove upstream and then walked to the body disposal site,” Yang Lin drew a route map in his notebook. “But why go the long way? Wouldn’t it be more convenient to drive directly to where the body was found?” He squatted down next to the tire tracks to observe. “The tire tread spacing is 150 centimeters and the wheelbase is 270 centimeters, which matches the parameters of a Volkswagen Lavida. This type of car is very common in nearby villages and towns.”

Yang Sen suddenly stopped under an old locust tree. There was a fresh scratch on the trunk, revealing light-colored wood. "The scratch is 120 centimeters high and 20 centimeters wide," he measured with a ruler. "There are traces of black pigment on the edges, and the composition is initially consistent with the paint on the corpse's jacket." A metal ring was buried in the soil under the tree. When he dug it out, he found it was a broken iron chain with a 10-millimeter diameter link and fresh rust on the surface.

"Is this chain related to the key found at the scene?" Yang Sen put the chain into the evidence bag, and Yang Lin shook his head: "The keychain is plastic, and this chain is more like something used to bind cargo. However, the mud and sand on the chain links are the same as those by the water, which means it was left by the suspect." He looked up at the tree branches, where a few leaves were covered with black fibers. "The murderer may have hidden the body under the tree first, and then dragged it to the water to dump it."

Upon reaching the abandoned dock, the rusty corrugated iron shed creaked in the wind. Yang Sen discovered clear tire tracks on the dock's concrete surface, perfectly matching the tire treads of the previous car. "The vehicle must have driven here," he said, covering the tire treads with rubbing paper. "The tire width is 18 centimeters, and the wheelbase is 270 centimeters, perfectly matching the specifications of a Volkswagen Lavida." The tire tracks stopped at the edge of the dock, leaving a clear skid mark on the ground.

“The suspect likely unloaded the body from the vehicle here,” Yang Lin pointed to the drag marks on the ground, which stretched from the end of the tire tracks all the way to the water’s edge. “The marks are about 45 centimeters wide and 3 centimeters deep, which is consistent with the shoulder width of an adult.” He found a silver button next to the drag marks, exactly the same as the one he had found before. “It has four round holes and the surface wear pattern is consistent, so it should come from the same piece of clothing.”

Yang Sen made an unexpected discovery in the tin shed at the dock: a black cloth bag discarded in a corner, its drawstring loosely undone. "It was empty inside, but the inner walls were covered with black fibers and mud," he said, opening the bag to examine it against the light. "It's about 60 x 40 centimeters in size, enough to hold folded clothes or tools." The label on the bottom of the bag was faded, but the remaining writing indicated it was made of canvas, commonly used on construction sites or for moving.

“This should be the black bag that Li Baochang saw,” Yang Lin said, examining the inside of the bag. “The fiber composition is exactly the same as what was found at the scene, and there’s a fresh tear at the bottom, probably from when it was filled with heavy objects.” He found a hair in the corner of the bag, 15 centimeters long, dark and straight. “We need to go back and do a DNA test; it might belong to the suspect or the deceased.”

Returning downstream for further investigation, Yang Sen made a new discovery at the abandoned sand quarry. Hidden behind a pile of rubble was a silver lighter. Unlike the previously found "Smooth Sailing" model, this lighter had the word "Peace" engraved on its casing, and the fingerprints on the bottom matched some of the previous ones. "Both lighters were used by the same person," he deduced. "The suspect may have carried two lighters, or perhaps one was accidentally dropped." (End of Chapter)