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

Yang Lin's bruises were worse than yesterday's, Zhang Kai's white coat had iodine stains on the cuffs, Zhang Hui's cigarette pack was half empty, and Wang Shuai's notebook was covered with sticky notes of surveillance screenshots. He pushed Qin Yanming's ID photo to the center of the table. In the photo, the taxi driver was wearing black overalls, his left breast pocket was bulging, and he smiled somewhat awkwardly at the camera.

Yang Lin stood up first and projected the photos of the scene onto the screen one by one. The first photo was a panoramic view of the body dumping site on the Beihe River. The murky river water shimmered with golden light, reeds swayed in the wind, and a warning line marked with a striking yellow line on the riverbank. "The on-site investigation area has been expanded to 200 meters upstream and downstream of the riverbank, with a focus on the abandoned dock, sand quarry, and surrounding woodland," his voice hoarse from staying up all night, his finger tracing an arc on the screen. "A size 44 shoe print was found on the bank of the body dumping site, with a stride length of 78 centimeters and a stride angle of 6 degrees outward. The estimated height is 178-183 centimeters, and the weight is about 70 kilograms. The shoe print extends from the riverbank to the water's edge, with a clear pause at the location corresponding to the body, and the sole pattern is inlaid with fragments of aquatic plants."

Suddenly, a black polyester fiber appeared on the screen, clearly visible under the microscope. "This fiber matches the composition of the deceased's work clothes lining," Yang Lin magnified the fiber details. "The cross-section is an irregular triangle, the linear density of a single fiber is 3.2 dtex, and the breaking strength is 4.5 cN/dtex. It has been found in drag marks at the abandoned dock and on rocks in the sand quarry." He paused, then pulled up a photo of an iron chain. The scratches on the chain links were particularly clear under the light. "A half-chain was found behind a pile of rubble at the sand quarry. The chain links are 10 millimeters in diameter, and there is fresh rust on the surface. The composition of the mud and sand is consistent with the location where the body was dumped, suggesting it was a tool used to bind the body, but no obvious bloodstains were found."

Zhang Kai opened the autopsy report, the rustling of pages breaking the brief silence. "The deceased, Qin Yanming, male, 41 years old, a taxi driver for the city company, cause of death determined to be mechanical asphyxiation," he read, his fingertip resting on a photograph of the choroid fossa on the neck, the dark red indentation still clearly visible amidst the decaying venous network. "There are circular finger marks on the neck, 1-1.2 cm in diameter, spaced 2.5-3 cm apart, extending from the left mandible to the right side of the neck, consistent with the force characteristics of strangulation. There is a complete fracture of the left greater horn of the hyoid bone, with sharp ends and slight callus formation." He switched to the lung photographs, scattered hemorrhages resembling scattered red millet grains. "Tardieu spots are present in both lungs, and the cardiac blood hemoglobin oxygen saturation is 62%, consistent with typical changes in death by asphyxiation."

"How precise can the time of death be?" Lu Chuan suddenly interjected, his pen twirling rapidly across his notebook. Zhang Kai pulled up a rectal temperature curve: "Rectal temperature 18.5℃, ambient temperature calculated based on river water temperature 15℃, combined with the degree of rigor mortis and the digestive state of the stomach contents, the time of death is determined to be between 10 PM on June 13th and 2 AM on June 14th. The person ate rice and meat 4-5 hours before death." He added, "The nail of the right index finger was freshly broken, with bleeding at the break point. A small amount of black fiber and skin tissue was extracted from the nail crevices. The fiber composition matches the polyester found at the scene. DNA testing is currently being conducted on the skin tissue."

Wang Shuai then reported on the riverside investigation. Sixteen split-screen surveillance images appeared on the screen, each marked with a timestamp. "There are many blind spots in the surveillance along the Beihe River embankment, especially in the area from 100 meters upstream of the body dumping site to the abandoned dock," he said, zooming in on a blurry blue sedan in the image. "At 10:02 PM on June 13th, municipal surveillance captured this sedan, which appears to be a Volkswagen Lavida. The last two digits of the license plate are '37'. A hand was seen sticking out of the passenger window, possibly discarding something, but the image was too blurry to confirm." He switched to the surveillance footage from the Wanghai Community convenience store. "At 8:30 PM on June 13th, a man wearing a black jacket and with a slightly hunched back bought Yuxi cigarettes and beer, paying anonymously via WeChat, making it impossible to trace his identity."

“Visiting surrounding villages and fishing spots yielded limited results,” Wang Shuai pulled up his visit records. “Aunt Li from Wanghai Village said she heard arguing on the riverbank on the evening of June 13, but the distance was too far to confirm the details; fellow angler Lao Zhou mentioned seeing a suspicious man wearing a black jacket and carrying a black cloth bag a few days ago, and when he inquired about the river section's surveillance footage, his description partially matched that of the man at the convenience store.” He sighed, “Qin Yanming’s last passenger information has not been found, the taxi’s GPS disappeared at 10:15 pm on June 13, and the vehicle has not been found to this day.”

Zhang Hui laid out Qin Yanming's driving route map on the table, drawing a straight line between the Beihe River embankment and Wanghai Residential Area with a red marker. "The deceased's driving record for June 13th shows that the last fare was to Wanghai Residential Area, with an agreed delivery time of 8:6 pm," he tapped his finger on the red dot on the route map, "The Beihe River embankment is the only route from Wanghai Residential Area back to the taxi company, a distance of about 3 kilometers." He pulled up Qin Yanming's social relationship list, "The key suspect is Zhao Gang, male, 38 years old, a building materials store owner, who had a dispute with Qin Yanming over a 6 yuan fare. On June 10th, he threatened Qin Yanming on the phone, 'Don't push your luck.'"

“Zhao Gang’s basic information matches the preliminary profile,” Zhang Hui circled Zhao Gang’s name in red. “He is 178 cm tall, weighs 72 kg, and owns a blue Volkswagen Lavida, purchased four years ago, which matches the model seen in the surveillance footage. On the evening of June 13, he claimed to be minding the shop, but there is no surveillance footage or witness testimony to corroborate this.” He paused, “More importantly, Zhao Gang has a fresh scratch on his right index finger, which he claims was caused while moving building materials, but the shape of the wound may be related to the skin tissue damage characteristics under Qin Yanming’s fingernails.”

The air in the meeting room seemed to freeze. Sparrows hopped and chirped outside, their sounds unable to penetrate the heavy atmosphere. "Now there are a few key questions," Lu Chuan said, tracing two lines on the table with his finger. "First, did Zhao Gang have the opportunity to commit the crime? Second, does the blue sedan in the surveillance footage belong to him? Third, who was Qin Yanming's last passenger? Was it related to Zhao Gang?" He looked at Yang Lin, "Could the chain and black bag found at the scene be linked to Zhao Gang?"

Yang Lin shook his head: "No fingerprints were found on the chain and the bag, only faint fiber residue, which needs to be compared with Zhao Gang's clothing. But based on the current clues, Zhao Gang's height, weight, and vehicle information all match the suspect's characteristics, and he has debt disputes and threatening behavior, giving him the motive and means to commit the crime." Zhang Kai suddenly added: "If the skin tissue under the victim's fingernails matches Zhao Gang's DNA, it will directly lock in the suspect. In addition, if Zhao Gang has a criminal record, there may be a matching record in the fingerprint database."

Li Bing suddenly put down his pen, his chair scraping half an inch off the floor: "I tend to think Zhao Gang is a prime suspect." (End of Chapter)