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

"The shape of this indentation indicates that the perpetrator had a ring on his right index finger with serrated edges, which may be an important identifying feature."

Xiao Lin took notes, his pen drawing clear lines on the autopsy report: "So, the water tank was just the dumping site, not the primary crime scene? Then where could the primary crime scene be?" Zhang Kai nodded: "It's very likely within the residential area, or even inside Building 3. The murderer chose the relatively hidden water tank to dispose of the body. Look at the composition of the rust on the deceased's clothing; it's completely consistent with the rust on the water tank's inspection port, indicating that the body was put in through the inspection port. This also explains why there are pry marks on the inspection port."

Finally, Zhang Kai used a ruler to measure the spacing of the finger marks on the victim's neck: "The distance between the thumb and index finger is about 8cm, and the width of the knuckles is 2.8cm. Combining these data with the footprints at the scene, the murderer should be an adult male, 178-183cm tall, possibly wearing a ring on his right hand, possessing considerable strength, and familiar with the neighborhood environment, knowing the structure of the water tank and the blind spots of the surveillance cameras." He closed the autopsy report, "These findings will provide a clear direction for the investigation. Finding the primary crime scene and the suspect with ring marks is crucial."

The smell of formalin in the autopsy room seemed to have faded somewhat, and the night outside the window grew even darker. Zhang Kai looked at the corpse on the autopsy table, as if he could see through the cold skin the night of that fierce struggle. Although the cause of death was clear, the killer's face remained hidden in the shadows of the water tank, awaiting further evidence to illuminate it. Xiao Lin carefully arranged all the specimens; these silent pieces of evidence would continue to tell the truth in the laboratory, guiding the investigators towards the end of the case.

While reviewing the autopsy results, Zhang Kai and Xiao Lin discussed the case. "The time of death was determined to be between 8 PM and midnight on September 10th, which basically matches the surveillance footage investigated by Wang Shuai and his team," Zhang Kai summarized. "The deceased had been in a struggle before death and had a physical altercation with the perpetrator. The skin tissue under the fingernails likely came from the suspect, which is important biological evidence. The finger marks on the neck indicate that the perpetrator used his right hand to strangle the victim, with a knuckle width of about 2.8 cm, suggesting a male with considerable hand strength."

Looking at the photo of the finger marks on the neck, Xiao Lin said, "Judging from the distribution and pressure of the marks, the killer must have been taller and stronger than the victim; otherwise, it would be difficult to create such obvious finger marks and a fractured hyoid bone." Zhang Kai nodded in agreement, "Based on Yang Sen's footprint analysis, the suspect's height is 178-183cm, which matches this assessment. In addition, the victim's stomach contents were normal, showing no signs of poisoning, ruling out the possibility of being drugged before being murdered; it was a sudden attack."

When the body was placed in the refrigerated cabinet, Zhang Kai's preliminary autopsy report was completed: "The deceased died of mechanical asphyxiation caused by strangulation. The time of death was between 8 pm and midnight on September 10. There was obvious struggle and resistance before death. After death, the body was thrown into the water tank of Building 3 in Anju Community for concealment." Xiao Lin sorted through the collected samples, including blood, stomach contents, nail crevices, and clothing fibers, which would be sent to the laboratory for further testing.

The smell of disinfectant in the autopsy room gradually overpowered the stench of decay. Zhang Kai removed his gloves, the coolness lingering on his fingertips. The life hidden in the water tank was slowly revealing its truth under the scalpel—a fierce struggle, a cruel strangulation, and finally, a hasty throw into the icy water. His identity, and the suspect's motive, remained like the fog shrouding the Anju residential area, awaiting further evidence to unravel. Looking out at the night, Zhang Kai knew the autopsy results would provide crucial directions for the next stage of the investigation; the hope of finding the killer lay hidden within these cold, technical data.

The fluorescent lights in the Criminal Investigation Division's information analysis room hummed softly at midnight, casting long, thin shadows. Zhang Hui crumpled the packaging of his ninth instant coffee into a ball and carefully tossed it into the trash can; the dull thud of the paper hitting the plastic wall was particularly jarring in the silence. The missing persons information on the screen flowed like an endless river; names, ages, and characteristics floated in blue light, already scrolling to entry number 876. The clicking of the mouse wheel made one's temples throb.

"Boss, is this crappy system from ten years ago?" Young officer Xiao Lin rubbed his red eyes, his knuckles circling his temples, the blue light from the screen casting deep shadows on his face. "Checking 'male, 35-45 years old, around 175cm tall' brings up over nine hundred results, but the photos are so blurry they're like mosaics, you can't even tell the features apart, how are we supposed to compare them?" He slammed the mouse down on the "exclude" button, the confirmation box that popped up looked like a mocking smiley face. "This 'Wang Jianjun,' has a scar on his left cheek, but the deceased's face was smooth, so we have to exclude him too."

Zhang Hui's fingertips hovered over the keyboard, the ashtray overflowing with cigarette butts, the top one still emitting wisps of smoke. "Check the forensic database again," his voice hoarse with a mixture of coffee and nicotine, "Male, height 175±2cm, age 38-42, right index fingernail broken, wearing blue polyester overalls, manual laborer (calloused hands), disappeared around September 10th." These keywords flashed white in the search box at the top of the screen, like an unsolvable code, trapping him in this quagmire of data.

Veteran detective Li Bing suddenly slammed his laptop shut, the chair legs scraping against the floor with a screeching sound that startled the pothos leaves on the windowsill. "This job is even more grueling than staking out," he said, tugging at his sweat-soaked, wrinkled collar. A musty smell of sweat mixed with the aroma of Master Kong braised beef noodles filled the air conditioning. "Last month, when we caught that car thief, at least we had a side profile from the security camera. Now, all we have is a blurry height and age; no distinguishing features." He pointed to the "Zhao Wei" entry on the screen. The man in the photo grinned, revealing a gold tooth. "Look at this one, a food delivery guy, 174cm tall, 39 years old—everything matches, but he's missing a piece of his right ear. The deceased's ear was perfectly intact, so we have to rule him out."

Xiao Lin suddenly started pounding the table like he'd been injected with adrenaline, almost making the keyboard jump. "Hey, hey, this 'Qian Ming' looks a bit like him! 39 years old, construction worker, 176cm tall, old injury on his right knuckles, went missing on September 9th." He zoomed in on the photo until it filled the entire screen; the man's features distorted in the blurry pixels, like an ugly worm. Zhang Hui leaned forward, his nose almost touching the screen, his fingertip pointing to the man's left chest in the photo. "No, he has a tattoo on his left chest. The forensic report didn't mention tattoos on the deceased. And this guy has double eyelids, the deceased had single eyelids, and his eye sockets were deeper." (End of Chapter)