Criminal Investigation Notes

In the conference room of the Huadu General Bureau, Lu Junchi withdrew his gaze and continued, “All the detailed information about the Fine Sand case is here. Today, everyone must work overtime and go through all the files of this case to fully understand the situation.”

He paused for a moment and then said, “We still have some time before the end of the workday. Xia Mingxi, you will compile the data. Zheng Bai and Qiao Ze, go back to the crime scene for another look. Qu Ming, you will coordinate with the other teams and gather all the relevant information. The personnel from Xing’s team can also be deployed as needed, so take Shao Lin with you.”

The team members nodded in agreement. Lu Junchi’s work assignments were always rational and clear.

The general process of solving a case involved several steps. First, the crime scene investigation, understanding the process of the crime, and reconstructing the scene as much as possible. Second, identifying the tools used in the crime and searching for various forms of evidence. Third, pinpointing the suspect and conducting interrogations and questioning.

Within these processes, continuous reasoning, investigation, and finding the motive behind the crime were also necessary.

Lu Junchi added, “Also, everyone, make use of the time. Pack up today, and starting tomorrow, rooms in the hotel next to the bureau will be available for temporary rest.”

The others left, and Xia Mingxi also took a stack of previous case files to organize and file them.

For a moment, only Lu Junchi and Su Hui remained in the conference room.

Facing Su Hui, Lu Junchi said, “Su Hui, about this case…”

Su Hui seemed to know what he wanted to say and interrupted him, “You don’t have to worry about me. No matter where I fall, I will climb back up from there. I have some understanding of the details of this case, even more so than others. And I hope to personally apprehend the killer.” Otherwise, he wouldn’t have actively sent a text message to Lu Junchi, hoping he would take over.

Both of them had reviewed the files of the Fine Sand case multiple times in the past. Even the detailed information recorded in those files wasn’t as known to Su Hui, who had experienced it firsthand.

Lu Junchi’s expression turned serious. “I’ve noticed that the method of deployment this time is completely different from before.”

Su Hui nodded. “I’ve also noticed that. I feel that this case has too many differences and similarities compared to the previous Fine Sand case. Fine Sand has always been strange and unconventional…”

Whether it was two years ago or two years later, there must be some truth to this case that they had yet to uncover.

Su Hui blinked and made a judgment, “Regarding this case, I might have had some misconceptions in the previous reasoning process. To avoid misleading you, I hope this investigation can be led by your approach.”

Having experienced the Fine Sand case, people often had ingrained thinking patterns and preconceptions, which could lead them into a maze. Lu Junchi had just been introduced to this case, so he might bring new perspectives to the solving process.

Lu Junchi said, “I have some ideas now and feel that we should start with the current case.”

After all, the Fine Sand case was quite old, and time would have destroyed much of the evidence. But with the new case, they could find more information.

Su Hui nodded in agreement, “Okay.”

The two of them quickly formulated the direction of the investigation and the basic plan.

Since several hours had already passed since the crime, there were some on-site videos, photos, and recorded testimonies from uninjured individuals.

Compared to Su Hui, whose vision was somewhat impaired, Lu Junchi was able to review the materials more quickly.

After going through them, he said to Su Hui, “I’ve found a common point between these two cases.”

Su Hui looked up and asked, “What?”

Lu Junchi replied, “In both of these bus explosions, they occurred after disputes between passengers.” He compared the testimonies and continued, “And both times, female passengers were harassed.”

During the previous investigation, Xing Yunhai had recorded the testimonies of all the passengers. They discovered that the bomb was found approximately ten minutes after a dispute among the passengers, and the man involved was still on the bus at that time.

Because the first explosion didn’t actually happen, they couldn’t directly link the explosion to this incident.

But if such a situation occurred twice, it would have a completely different meaning.

Lu Junchi compared the passenger lists of the two buses and confirmed that the same person was involved in the disputes. “The deceased who harassed people on the bus is this person named Duan Siyuan, and he appeared on the previous bus as well.”

After saying that, he pointed out the matching names to Su Hui. Then Lu Junchi sent the information to Qiao Ze for further verification.

“Two different buses, different routes, different times, but the same person appears on both buses, and he is also one of the deceased. He has a high possibility of being the target,” Su Hui said as he squinted his eyes while reading the testimonies. “There is another common point: when female passengers had disputes with this person, the other passengers remained indifferent, and the matter was not resolved. This may be one of the conditions for the crimes to occur.”

Lu Junchi nodded earnestly. “Then let’s follow this person and see if we can uncover more.”

The information about the deceased was quickly transmitted to them.

Duan Siyuan, 44 years old, 172 centimeters tall, with dark and slightly thin skin.

From the photos, his gaze seemed dull and clouded.

If one could directly access his thoughts, they would discover that he was constantly thinking about those things…

His whole life had been swallowed by that incident.

Desire, endless desire, he had become a slave to his own body.

This man was one of the victims in the accident, and he had a previous altercation with a female passenger before the incident, which led her to hastily leave the bus.

Lu Junchi looked at the information for a while and commented, “This man is truly disgusting.”

The first segment of the video recording was complete. It showed Duan Siyuan relentlessly pursuing the girl, taking advantage of the crowd and the arrangement of seats on the bus to corner her into a dead-end. She was terrified, but he showed no remorse.

Finally, this person died in an explosion on the bus, and from the photos of his body, it was clear that he didn’t survive.

Su Hui looked at the background information on Duan Siyuan.

Duan Siyuan came from a family of three siblings, being the youngest. He had been spoiled by his parents since childhood. With low intelligence and frequently being bullied, his academic performance was poor, and he only graduated from junior high school.

After becoming an adult, Duan Siyuan’s family had a few properties from demolition projects. Besides living in one of them, he could also collect rent. However, he didn’t work seriously and spent his days idly.

After his parents passed away, his sisters didn’t bother arranging a marriage for him, so he wandered around in those buses, public transportation, and subways. He even spent more time on those vehicles than at home.

This was a habitual offender with a long criminal record, starting from eighteen years ago.

However, due to his intellectual disability and aggressive behavior, many people avoided him.

One of his sisters had obtained a mental

health certificate for him, claiming that he had a mental illness, and the things he did were not significant. As a result, he had never been properly punished.

After going through the witness statements, Lu Junchi patiently called both of Duan Siyuan’s sisters. They didn’t express any grief over the deaths of their family members; instead, they seemed relieved and assured the police of their cooperation.

Lu Junchi asked Su Hui, “Is there a possibility that the suspect who planted the bomb is a woman this time?” He thought that if a woman had been harmed by Duan Siyuan’s actions, she might seek revenge.

Su Hui lowered his head and said, “We cannot exclude the possibility of a male seeking revenge for his girlfriend or wife. However, if Duan Siyuan is indeed the target, the perpetrator might be physically weaker and in a vulnerable position.”

Lu Junchi accessed the system and checked, then summarized, “I have compiled the records in our system regarding Duan Siyuan, and there have been 43 reports.”

However, none of these 43 reports led to any final action against him. They either reached a settlement or were dropped without further investigation.

Su Hui responded indifferently, “The number of victims is far more than that. Most of them probably didn’t report the incidents.”

Using Duan Siyuan’s associated phone numbers, he found some of his accounts, where he even posted some upskirt photos openly on the internet.

Moreover, despite being middle-aged, it seemed that this person’s desires remained unabated. He posted frequently and was quite active.

Su Hui summarized while propping his chin with his hand, “He is an unemployed vagrant. Every day, after waking up and having lunch at his doorstep, he gets on a bus and randomly sits anywhere. Sometimes, even after dinner, he still hasn’t had enough. So, on average, he creates at least two to three victims every day.”

In other words, there could be nearly a thousand victims in a year, and over ten thousand victims in a decade.

Only a minority of people chose to report the incidents.

Duan Siyuan’s behavior could cause substantial harm to those women, making them feel uncomfortable, cry, even have nightmares, and develop fear towards men that they couldn’t escape from even after many years.

Such incidents were terrifying and tragic, and there were more than just a few men like Duan Siyuan in the city.

There was no effective way to restrain such situations.

Hearing this, anger flickered in Lu Junchi’s eyebrows. “Men who can’t control their lower desires are no different from beasts…”

Su Hui nodded in agreement. “They should have been castrated long ago.”

Lu Junchi gathered all the information and sighed, “There are too many potential victims, and it’s difficult to continue tracing this line.”

He had initially thought that uncovering Duan Siyuan’s actions would lead them to the culprit, but now it felt like entering a maze.

A seasoned old hooligan casting a wide net, with numerous potential victims, it was impossible to determine who the suspect could be for now.

“In the previous sand explosion cases, the victims were random individuals. The perpetrators did not exhibit this kind of ‘justice’ trait,” Su Hui coughed a few times while covering his mouth and then asked, “How far was Duan Siyuan’s position from the location of the explosion?”

Lu Junchi replied, “One row away. However, the people on the bus kept changing, so it’s uncertain whether he changed seats after the bomb was placed…”

Duan Siyuan was a despicable scum, but he was just one of the deceased.

He was likely the target of the perpetrator.

However, the police cannot yet confirm whether he is the actual target of the perpetrator. They can only consider these as clues.

Su Hui pondered, and there have been only two cases related to the bus explosions so far.

The connection between the cases and Duan Siyuan was mere speculation. Perhaps the perpetrator committed the crimes randomly, as usual, and Duan Siyuan happened to be on those two buses by chance.

Reaching this point, it was indeed difficult to continue with this starting point.

The two of them studied until the end of their workday. Lu Junchi closed the files and said, “Let’s leave it at this for today. Tonight, I’ll review other records and the results of the on-site investigation. Tomorrow, the explosive disposal experts from the SWAT team will arrive. Hopefully, they can provide us with some leads.”

Su Hui asked, “Do you have any other ideas?”

Now they had to race against time to stay ahead of the perpetrator.

Lu Junchi replied, “I want to study the scattered sand at the scene thoroughly.”