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

Lu Chuan nodded and said, "Okay, I will personally supervise the technical department and have them expedite the testing. After you two lead the investigation team back, immediately compile the on-site investigation report, recording every detail of the investigation and the collection of physical evidence. At the same time, conduct a preliminary analysis of the collected footprints and traces to provide direction for subsequent investigation work. In addition, arrange for personnel to comprehensively retrieve the surveillance footage of the Oriental Logistics Park over the past month, focusing on the area around the factory buildings to see if any suspicious persons or vehicles can be found."

"Understood!" Yang Lin and Yang Sen responded in unison. The two then led the investigation team back to the Criminal Investigation Division, immediately commencing work on compiling the crime scene investigation report and analyzing physical evidence. Simultaneously, the technical department initiated physical evidence examination procedures, conducting comprehensive tests on the extracted bloodstains, fingerprints, fibers, hair, and other samples.

Back in the investigation department office, Yang Lin and Yang Sen divided the work. Yang Lin was responsible for compiling the investigation report, meticulously recording every step of the on-site investigation, every piece of physical evidence collected, and the on-site environment, ensuring that the report was accurate, detailed, and complete. Yang Sen was responsible for conducting a preliminary analysis of the extracted footprint models, comparing the characteristics of the footprint soles, wear, stride length, and stride width to make a preliminary judgment on the suspect's height, build, and walking habits.

"Based on the footprint characteristics, the suspect's height should be between 178 and 182 centimeters, with a slender build. He walks with his weight shifted to the left, and may have a slight left-foot pigeon-toed gait," Yang Sen said, carefully measuring and analyzing the footprint model. "The moderate wear on the soles indicates that these leather shoes have been worn for some time and are not new. The checkered sole pattern is quite common; many brands of leather shoes on the market have similar patterns, so we cannot determine the specific brand of the shoes based on the pattern alone."

While organizing the report, Yang Lin said, "If the fingerprint sample can be successfully matched with the national fingerprint database, we can directly identify the suspect. The composition analysis of the fiber sample is also crucial. If we can determine that it is a fiber from a specific brand and style of clothing, we can narrow down the scope of the investigation. In addition, if the fingerprint on the mineral water bottle matches the fingerprint on the mechanical handle, we can further confirm that it was left by the suspect. At the same time, we can conduct DNA testing on the mineral water bottle to see if we can extract the suspect's biological sample."

At 2 PM, the technical department reported the preliminary test results: "The blood samples extracted from Yang Lin and Yang Sen were confirmed to be the blood of the deceased, with no blood residue from other individuals found; the fingerprint samples have undergone preliminary processing, with the fingerprint extracted from the mechanical handle being the clearest and entered into the national fingerprint database for comparison, but no matching results have been found yet; the fiber sample, after compositional analysis, was determined to be a wool and polyester blend, commonly found in winter outerwear; among the hair samples, 3 strands belonged to the deceased, and 2 strands belonged to an unknown male, preliminarily judged to be left by the suspect, and DNA sequencing has been performed, currently being compared with the national DNA database; the metal button was tested and found to be an ordinary industrial button with no special markings, and the manufacturer could not be traced; the fingerprint extracted from the mineral water bottle matched the fingerprint on the mechanical handle, confirming that it was left by the same person, but no valid DNA sample was extracted from the bottle."

Upon receiving the preliminary test results from the technical department, Yang Lin and Yang Sen were invigorated. "The unfamiliar male's hair and clear fingerprints are important clues. As long as they can be matched with the database, we can identify the suspect," Yang Sen said. "The wool-polyester blend fibers indicate that the suspect may be wearing a winter coat. Considering the current season, this feature has some investigative value."

Yang Lin added, "The fingerprints on the mineral water bottle match those on the mechanical handle, further confirming that these fingerprints were left by the suspect. Although no DNA sample was extracted, if the fingerprint comparison yields results, it can still identify the suspect. In addition, the identity of the deceased remains a mystery. We need to combine the deceased's physical characteristics with information on recent missing persons for comparison and investigation."

Subsequently, the two incorporated the preliminary test results from the technical department into the on-site investigation report, along with footprint analysis, trace analysis, and other related content, forming a complete on-site investigation report, which they then submitted to Lu Chuan. After reviewing the report, Lu Chuan immediately convened an investigation meeting to deploy follow-up work: "Based on the on-site investigation and preliminary examination results, we have obtained some characteristics of the suspect, including height, build, walking habits, clothing characteristics, and fingerprint and DNA information. Next, we will focus on the following: First, continue to await the fingerprint and DNA comparison results, assigning dedicated personnel to monitor the database. Once a match is found, we will immediately launch an arrest operation; second, conduct a city-wide search based on characteristics such as wool-polyester blended fibers, size 42 checkered leather shoes, and black metal buttons, focusing on clothing markets, shoe stores, hardware stores, and other similar locations; third, retrieve surveillance footage from the Oriental Logistics Park and its surrounding area over the past month, organizing dedicated personnel to review each frame to find individuals and vehicles matching the suspect's characteristics; fourth, review recent missing persons information across the city, comparing it against the physical characteristics of the deceased to confirm their identities; fifth, expand the scope of the investigation beyond the Oriental Logistics Park itself, conducting comprehensive visits to residents, businesses, and scrap metal collectors in the surrounding area to identify any suspicious individuals or unusual circumstances."

After the meeting, each investigation team immediately began their work according to the plan. Yang Lin and Yang Sen remained with the investigation department, conducting in-depth analysis of the traces and physical evidence collected at the scene, while also assisting the technical department in subsequent evidence examination. They repeatedly studied the characteristics of the footprints at the scene, attempting to deduce information such as the degree of wear and stress points from details like the footprints; at the same time, they also further observed the extracted fiber samples, hoping to discover more hidden features and provide a more precise direction for the investigation.

"Judging from the wear and tear on the footprints, the suspect's left shoe sole is more worn than his right shoe, which suggests that he may have been engaged in work that requires prolonged standing and walking, or that he has a habit of bearing weight on one side." Yang Sen analyzed the footprint model again in detail and said, "The larger stride and faster walking speed indicate that the suspect has good psychological qualities and was able to remain calm and quickly escape the scene after committing the crime."

Yang Lin held the fiber samples and examined them carefully under the microscope: "The dyeing process of these fibers is quite ordinary; they should be fibers from mid-to-low-end clothing, and the price shouldn't be too high. Furthermore, there are slight signs of wear on the fiber surface, indicating that this coat has been worn for quite some time, suggesting the suspect's financial situation is probably not very good." (End of Chapter)