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

“The boot prints, palm prints, yellow plastic rope, and suspected bloodstains found so far all point to the same suspect, who is 178-183 cm tall, wears size 43 boots, and may be carrying lock-picking and cutting tools,” Yang Lin wiped the sweat from his forehead. “But these clues need to be tested in the laboratory to confirm their relevance, such as whether the palm print matches the fingerprints on the cigarette box, whether the suspected bloodstains belong to the victim, and whether the metal fragments came from the murder weapon.”

Yang Sen nodded, flipping through the investigation records: "The deceased's identity is still a mystery. There were no ID cards, cell phones, or other items on him that could prove his identity. The cigarette box and buttons are also common items, so they cannot be directly linked to any specific person." He pointed to the brown soil on the deceased's trouser leg, "This soil contains a lot of sand and humus, which is not the type of soil commonly found in urban areas. It may have come from the suburbs or a construction site. We need to test the soil composition to determine its origin, which may help us find the area where the deceased was active before his death."

"The black SUV is also a crucial clue, but so far we only have Li Baojun's description and the metal friction marks on the alley wall," Yang Lin added. "It's uncertain whether the municipal surveillance cameras can capture the vehicle, and even if they do, it will be difficult to trace it without a clear license plate. Moreover, the suspect has a strong sense of counter-surveillance, choosing the transfer station where the surveillance cameras were damaged as the location for dumping the body, and also cleaning up some of the traces, which has increased the difficulty of our investigation."

By the time the two finished their expanded investigation, it was already noon. The technicians sorted and packed 15 pieces of evidence, including palm prints, fingerprints, suspected bloodstains, metal fragments, and soil samples, into boxes, preparing to send them to the criminal investigation branch laboratory. Yang Lin looked at the boxes full of evidence, his brow still furrowed: "Although we've found quite a few clues, they all need further testing to determine their value. Currently, there are no leading leads; we don't know who the suspect is, nor do we know the victim's identity. The case is still at a standstill."

Yang Sen put away his investigation tools, his tone tinged with helplessness: "We can only wait for the lab results. Hopefully, the palm print and fingerprints will match, and the soil composition will determine its origin. Only then can we have a direction for the next step of the investigation." He glanced at the body still lying face down on the ground. "As long as the victim's identity is uncertain, we cannot understand his social relationships or find any possible motives, making it difficult to advance the investigation."

The two men organized their investigation records and reported to Lu Chuan, who was waiting at the scene. "The expanded investigation yielded one palm print, two fingerprints (one complete and one incomplete), 18 footprint rubbings, eight fiber samples, three suspected bloodstains, two metal fragments, five soil samples, and one piece of yellow plastic rope," Yang Lin said, pointing to the evidence box. "All evidence needs to be sent to the laboratory for fingerprint comparison, DNA testing, and component analysis. At present, no major clues have been found that directly point to the suspect or the deceased."

Lu Chuan nodded, his tone calm: "Thank you for your hard work. First, send the evidence back to the branch and have the technical department expedite the testing. We must get the results as soon as possible." He looked around the transfer station, "At the same time, arrange for people to visit the shops and residents on both sides of the alley to find more witnesses, retrieve municipal surveillance footage within a 3-kilometer radius, and focus on investigating the whereabouts of the black SUV from 8 p.m. last night to 5 a.m. this morning."

Sunlight streamed through the roof of the transfer station, casting dappled shadows on the ground. Yang Lin and Yang Sen loaded the evidence into the police car, knowing that although the expanded investigation had uncovered many clues, solving the mystery would still require precise laboratory testing and further investigation. The victim's identity remained unknown, and the suspect's whereabouts were elusive; this race against time had only just begun.

As the police car drove away from the transfer station, Yang Sen watched the alleyway recede into the distance outside the window, recalling the fragmented fingerprint left in the soil—perhaps this tiny fingerprint held the key to unlocking the truth of the case. He took out his investigation logbook and solemnly wrote in the "Clues to be Tested" column: "1. Palm print and cigarette box fingerprint comparison; 2. Suspected bloodstain DNA testing; 3. Soil composition analysis; 4. Metal fragment material identification," each item carrying the hope of uncovering the truth.

Back at the Criminal Investigation Division, the two handed over all the evidence to the technical department, repeatedly urging them to expedite the process. The technical staff took the evidence and promised to issue a preliminary test report within 24 hours. Yang Lin and Yang Sen sat wearily on a bench in the corridor—the morning's intense investigation had left them parched, but thinking of the unsolved mysteries, they immediately straightened their backs, awaiting the new breakthroughs the test results would bring.

In the municipal monitoring room along Heping Road, the cold light from the screen reflected on Wang Shuai's face. His eyes were fixed on the vehicles flashing by on the screen, his fingers tapping repeatedly on the keyboard, replaying the surveillance footage from 8 pm to 5 am on August 15th frame by frame. Most of the surveillance footage had slight snow-like noise, and the insufficient light at night made the edges of the images somewhat blurry, but in order to find the "black SUV with broken taillights" that Li Baojun had mentioned, Wang Shuai dared not slack off in the slightest. The coffee on his desk had gone cold, and the ashtray was piled high with cigarette butts.

"Team Leader Wang, look here!" Team member Xiao Chen suddenly pressed the pause button and pointed to the screen in the lower right corner. At 10:12 PM on August 15th, a black SUV slowly drove into the surveillance range of the intersection of Heping Road and Jianguo Road. The car had smooth lines, and the left taillight was obviously damaged, revealing the red light inside, which perfectly matched Li Baojun's description of "a black SUV with a damaged taillight." "The vehicle model looks like a Haval H6, 2022 model," Xiao Chen zoomed in on the image, "The license plate ends in '73,' but the characters at the beginning are obscured by tree branches and are not very clear."

Wang Shuai leaned closer to the screen, carefully observing the vehicle's details: "The driver was wearing a dark top and a baseball cap, the brim pulled low, so only the outline of his face could be seen. He was of medium build, which initially matched the suspect's height of '178-183 cm' as estimated from the on-site investigation." The vehicle stopped at the intersection for about 30 seconds, then turned right onto Heping Road, heading towards the garbage transfer station. "The time period, vehicle type, and taillight characteristics all match too well; it's very likely the vehicle driven by the suspect."

To track the vehicle's trajectory, Wang Shuai retrieved all municipal surveillance footage along Heping Road. At 10:18 PM, the black SUV appeared in the surveillance footage 500 meters east of the garbage transfer station. The vehicle slowed down noticeably, stopped at the roadside for about one minute, and then continued driving forward, disappearing into the blind spot of the surveillance cameras ahead. At 10:35 PM, the vehicle reappeared in the surveillance footage at the intersection of Heping Road and Dongfeng Road, heading towards the city center. The damaged taillights were particularly noticeable in the night.

"Immediately check the black Haval H6 with license plate ending in '73'!" Wang Shuai ordered into the walkie-talkie. (End of Chapter)