The Last Mr. Dongguo

The projector light shone on the screen, displaying a series of photos of the crime scene. Although they were photos, the horrific scene was still visually impactful. Everyone clenched their fists and gritted their teeth, their faces reflecting pity for the victims and hatred for the perpetrator.

"Two lives lost in three days. I don't want to hear any more speculation. What I want today is concrete evidence—evidence that can bring the killer to justice within 48 hours." Cheng Luan swept his gaze across the crowd, finally settling on Bai Xin. "How's the investigation into the relationship between the two victims going?"

Bai Xin took the mouse and clicked it twice, projecting photos of the two deceased and their relationship diagrams onto the screen.

"The first victim in the mulberry paper case was named Feng Zi, 40 years old, from Huze City, and was the owner of Feng Zi Electronics Factory. The scene of death was in front of the gate of Feng Zi Electronics Factory. The second victim, Wei Li, was the office director of Feng Zi Electronics Factory."

Fengzi Electronics Factory is facing bankruptcy due to financial problems. Production ceased a week ago, and all employees have been laid off early. I also interviewed some of the factory's employees, and they were mostly dissatisfied. The factory had a total of 78 employees, but due to the factory's closure, detailed personnel information is currently unavailable.

"Fei Li, tell me your thoughts." The criminal investigation captain took the lead in smoking, and each time the several pipes filled the conference room with smoke. Cheng Luan looked at Fei Li through the gaps in the white smoke, hoping that Fei Li could give a clear direction for the case.

"First, the murderer is male, weak and thin, or suffering from an illness. He is cautious and always feels inferior to others. Recently, his family has suffered a major upheaval, which led to the exposure of his simple personality, resulting in a violent murder to achieve his inner satisfaction." Fei Li took a sip of milk and searched for the crowd's responses through the clouds in front of her.

Bai Xin fanned the smoke in front of him, looking at Fei Li with confusion: "What is a simple personality type?"

"Simple personality, as the name suggests, is a type of person who tends to be submissive and keeps their bottom line very low in daily life. Such people seem to be content with their lot; as long as their bottom line isn't crossed, they'll tolerate everything and live a peaceful life. However, if someone breaks this balance, they will unleash years of pent-up frustration in an instant, acting recklessly and without restraint. And once they commit a crime, it's very likely to be a series of offenses." Li Mengying projected some cases of simple personality types onto the screen, then nodded to Cheng Luan.

"Amazing, Fei-ge is truly amazing. One sentence from him has us completely in awe." Bai Xin looked at Cheng Luan, seemingly giving Fei Li a thumbs up on Cheng Luan's behalf.

"Furthermore, the killer placed great emphasis on ritual in his killings. The act of pasting the mulberry paper with the official's name on it, making Feng Zi kneel with his face up to the sky, felt like a punishment from heaven. The same goes for Wei Li; a woman's most important thing is her appearance and skin, and the killer's act of eating her with fish was also a form of punishment. As for the killer calling himself 'the last Mr. Dongguo,' it's also a way of telling people that he was originally a kind Mr. Dongguo, but unexpectedly, he was blackmailed by wolves. 'The last' should be the killer's own end." Fei Li waved her hand, taking the... "Looking at the feces and lab reports at the scene, I explained, 'This is the feces I found at the scene. After testing, it turned out to be the feces of a plant called a flower-loving beetle. Flower-loving beetles don't like just any flower; they prefer the 'lover's flower.' Therefore, where there are flower-loving beetles, there must be lover's flowers. However, we didn't find this type of flower at the crime scene. But through the sand and a small amount of pollen surrounding the feces, I created a DNA profile. Once we find this type of flower, the DNA profile will lead us to where the flower-loving beetle should have been, and we'll be close to the killer.'"

"Can sand and pollen be used to create DNA maps?"

"Of course, plants and animals also have genetic material. If plant fragments, seeds, pollen, or similar substances are found on the victim's or the murderer's clothing, they may match the pollen found on the victim's body, clothing, and at the site where the body was dumped. This not only allows us to determine whether they come from the same type of plant through testing, but we can also collect pollen from trees near the locations where the suspect, victim, and body were found to create DNA profiles. If the comparison shows a perfect match, the murderer can be identified as a person connected to the case, and we can pinpoint not only the tree species but even which tree it was. This would link him to the body and the site where the body was dumped."

Sand is a silicate, meaning it's essentially glass. Each grain of sand is a hard crystal, and traces can be found: sand grains vary in size, shape, color, refractive and reflective properties, and chemical composition. These differences are often used to determine whether a particular sample originated from a specific location. I summarize these as the "DNA" of sand; some animals may nest in one place and not another; their feathers, nesting materials, or feces may also be found in the sand of another place. The flower-loving insect here is our target.”

"Okay," Cheng Luan stood up, walked to the map, connected the two crime scenes with straight lines, and drew a circle with the midpoint as the center. "Our next objective is to search within a five-kilometer radius of this point, focusing on the employees of Fengzi Electronics Factory. We need to find a single-story house, an honest man who loves to grow love flowers, and lives alone and is ill. We must catch him within 40 hours to prevent a third case from happening."

The ticking of the second hand, like a death knell, pressed down on Cheng Luan, making it hard for him to breathe. Twenty hours had passed. Everyone he could send out had been out visiting households, and Cheng Luan himself, along with Bai Xin, had visited nearly a hundred, but none of them matched Fei Li's profile. The search area had expanded from five kilometers to ten kilometers. Cheng Luan looked even more haggard, his once well-groomed beard now appearing weak and lifeless. Cheng Luan lowered his head wearily, feeling a buzzing in his head. It was as if a voice kept telling him that Fei Li was right in front of him, yet it also seemed elusive and unattainable.

"Form teams, form teams..."

Cheng Luan was awakened by a series of shouts. He shook his head and tried to focus his vision before he could see that Li Mengying was standing in front of him holding a computer.

"Captain Cheng, we found him." Li Mengying placed a photo in front of Cheng Luan. "It's him, Wu Lian. All the conditions match Fei Li's profile, and I've also checked. He's also an employee of Fengzi Electronics Factory. In addition, he has a record of buying 'love flowers' every year. Fei Li went to Wu Lian's residence in advance, but didn't find him. He only found an old tricycle and a medical certificate. The appointment time is today, and the doctor's name is Hu Lan."