freenovelworld Chapter 1001 The Corpse Under the Bridge
Chapter 1001 The Corpse Under the Bridge
He carefully picked up a bloodstained stone next to the body with tweezers. "The bloodstains and hair on the surface of this stone need to be sent for testing immediately."
Xiao Sun then used a laser rangefinder to measure the scene: "The bridge arch is 500 meters from the nearest road, and vehicles cannot drive directly in. The murderer must have carried the body on foot or used a flatbed cart or similar tool." He pointed to the ground, "Look at these drag marks, the body was dragged in from the west side. We should be able to find more traces and evidence along the way."
Li Ming crouched down and lifted the tattered plastic sheet covering the body. The deceased was wearing a black coat stained with mud, its pockets ransacked. "Wallet and phone are gone; this is clearly a premeditated crime," he said, turning to his team behind him. "Expand the search area, focus on checking nearby surveillance footage, and retrieve information on all vehicles that have passed through the vicinity in the past week."
After returning from visiting the surrounding villages with his team, Xiao Wang looked grave: "Team Leader Lu, the villagers nearby said they've heard strange noises at night these past few days, but they all thought it was just stray dogs. The only valuable clue is that the shop owner remembers a white van circling around the area several times last night around 10 p.m.
Li Ming quickly wrote down the keywords on the whiteboard: "Disfigurement, missing property, white van. The murderer wanted to hide the victim's identity while taking the valuables; the motive is not simple. Xiao Yang, get the autopsy report out as soon as possible; Xiao Wang, continue investigating the white van; Xiao Sun, pull up all the surveillance footage within a two-kilometer radius of the bridge underpass and watch it frame by frame!"
As dusk deepened, the investigation under the bridge continued. The forensic doctor's lamps cast beams of light in the darkness, illuminating the victim's bluish-purple face. Li Ming gazed at the flashing police lights in the distance, knowing that the investigation into this case had only just begun.
The air beneath the bridge arch was thick with the stench of decay and damp earth. Xiao Yang wrapped the strap of his Nikon D850 camera around his wrist twice, and attached his Nikkor Micro 60mm macro lens. This lens, designed specifically for photographing physical evidence, could clearly display scratches as small as 0.1 millimeters on the CMOS sensor. He knelt three meters to the east of the body, adjusting the level on his tripod. Through the viewfinder, the body's contorted posture against the weathered rock face of the bridge arch created a somber and oppressive scene.
“ISO 200, aperture f/8, shutter speed 1/125,” Xiao Yang muttered to himself, his fingers rapidly sliding across the multi-function buttons on the back of the camera. To avoid glare on the evidence surfaces, he used a ring diffuser, the white light evenly enveloping the scene. With a soft click of the shutter, the first overview photo was captured permanently. He continued shooting clockwise with a 120-degree overlap, these photos would later be stitched together into a 360-degree panorama using PTGui software, ensuring no corner was missed.
Xiao Sun was adjusting the Faro Focus 3D laser scanner. The blue-green beam emitted by the instrument wove a fine grid onto the rock wall. "Set the scanning accuracy to 2 millimeters, and the dot pitch to 0.5 millimeters," he said into the walkie-talkie. The device's built-in SLAM algorithm began building a 3D model of the scene in real time, collecting 2 million point cloud data points per second. When the scanner's laser swept across the corpse, Xiao Sun deliberately increased the scanning density to 1 millimeter to ensure that every scratch on the deceased's body was accurately recorded.
"Look for drag marks," Xiao Sun suddenly pointed to the ground. The dried-up riverbed was covered with a layer of fine sand, and an irregular drag mark, about 20 centimeters wide, snaked its way in. Xiao Yang immediately switched to a UV lamp. Under the 365nm wavelength, the fiber residue, previously indistinguishable to the naked eye, showed a faint fluorescence. He quickly switched to a UV filter, using long-wave ultraviolet photography technology, and adjusted the exposure compensation to +1.5EV, allowing the fibers that might have come from the killer's clothing to be clearly visible in the photograph.
While photographing the shoe prints, Xiao Yang took out fingerprint powder and gently sprinkled it on the sand. Under side lighting, the tiny particles at the edges of the shoe prints produced diffuse reflection, making the 4.5-centimeter-wide lines clearly visible. He placed a scale and compass next to the shoe prints and took three sets of photos from directly above, at a 45-degree angle, and at a 90-degree angle. "These should be size 42 work shoes," Xiao Yang noted, numbering the photos QZ-007-01 to QZ-007-03.
A spot resembling bloodstains on the rock wall of the bridge arch caught Xiao Sun's attention. He set up a stereo microscope, and through the eyepiece, the dark red mark appeared as an irregular splatter pattern. "The blood droplets are distributed in a satellite pattern, with an impact angle of about 30 degrees." He used an electrostatic adsorption device to collect the tiny blood droplets that might carry DNA information onto transparent tape, and then placed it in a vacuum drying oven. "We need to do ABO blood typing and STR typing as soon as possible," he told Xiao Yang.
When handling the body, the two used a layered examination method. Xiao Yang first used a soft-bristled brush at a 15-degree angle to clean the surface of the clothing, collecting three hairs of different lengths from the collar of the coat, which were then sealed into separate evidence bags. When he lifted the victim's blood-stained shirt, Xiao Sun immediately activated a multi-band light source, illuminating a 0.3 square centimeter light brown stain below the victim's left collarbone. "It might be dried saliva," Xiao Yang said, taking out a moistened cotton swab and, following the principle of vertical sampling, collecting three samples from the center and edges of the stain.
Upon discovering the bloodstained stone at the scene, Xiao Sun placed it under a stereomicroscope. At 40x magnification, the tiny fragments of tissue embedded in the stone's depressions were clearly visible. Holding his breath, he carefully separated the samples with tweezers, placed them in sterile tubes, and immediately affixed unique labels containing the case number, collection time, and collection location. "Hopefully, these will match the deceased's DNA," Xiao Sun said, a hint of expectation in his voice.
The entire investigation process strictly adhered to the principle of "fixing first, then extracting." Whenever new evidence was discovered, Xiao Yang would first use a scale, compass rose, and evidence number plaques to create a map, adjusting the white balance to ensure accurate color reproduction. When photographing blunt force injuries on the deceased's face, he specifically used a ring flash to eliminate shadows, combined with a reflector for supplemental lighting, making the scuff marks at the edges of the wounds clearly visible. Simultaneously, Xiao Sun used a total station to record the three-dimensional coordinates of each piece of evidence, precisely marking them on the site model.
The last rays of the setting sun shone through the bridge arch onto the survey box. Xiao Yang checked the photo counter in the camera; 137 sets of valid photos had already been taken. He rubbed his aching shoulders and looked at Xiao Sun: "Besides the usual physical evidence, we haven't found any decisive clues." Xiao Sun stared at the 3D model's display screen; the scene images composed of point clouds gleamed coldly: "Even the shoe prints have been deliberately destroyed; there are obvious drag marks and erasures at the edges."
Suddenly remembering something, Xiao Yang pulled up a photo of the deceased's pocket. In the image processing software, he increased the contrast by 30% and the brightness by 15%, and sure enough, he found several thin silver-gray lines between the fibers of the pocket lining.