Diary of a Criminal Investigator-Chapter 346: Results of the Sweep

Cheng Zihao is forty-one years old today. After graduating from the police academy, he started working at the Public Security Bureau in Liangzhou.

However, when Cheng Zihao first joined, he was not a detective but was assigned to work with the traffic police unit.

Twenty years ago, the workload for traffic police wasn’t as heavy as it is now. There weren’t many cars on the roads back then, so the work was relatively relaxed.

Cheng Zihao didn’t need to stand under the sun directing traffic every day.

But indeed, traffic police didn’t produce many talents. There was a sense of settling into a monotonous life right away, seeing through to retirement from the beginning of the job.

Different eras shape different life attitudes. The pace of work and life twenty years ago was vastly different from today.

Cheng Zihao was a person not content with an ordinary life; he longed for criminal investigation work the most.

Fortunately, there was an opportunity at that time. While patrolling the street, Chen Zihao caught a thief.

This guy was a repeat offender with quite a few cases on his hand. Cheng Zihao received a commendation for his actions back then.

It was this commendation that caught the attention of the Criminal Investigation Team leader at that time, who was short-staffed, so he proactively brought Cheng Zihao onto the team.

Cheng Zihao has now been a detective for 20 years. He is currently the deputy leader of the first action group of the Liangzhou City Criminal Investigation Team.

Three years ago, Cheng Zihao was the main investigator in the dismembered body case in the sewage canal. After the case became a cold case, it was assigned to him by the team.

As long as there was an opportunity, or if he heard of any distinguished detectives, Cheng Zihao would try to inquire and have them look over the files. 𝕗𝚛𝚎𝚎𝐰𝗲𝗯𝗻𝚘𝚟𝚎𝗹.𝕔𝐨𝕞

Last week, he visited Haizhou City for a meal with his brother-in-law’s family, and upon hearing Qin Yong mention Lu Chuan, he sent the files over to Qin Yong to ask Lu Chuan for help.

He originally intended to just give it a try since many people had already examined the case.

There were multiple provincial experts, let alone Lu Chuan, who is a crime scene detective.

But the crime scene left almost nothing behind in terms of evidence.

Cheng Zihao did not expect Qin Yong to respond so quickly with what turned out to be an important lead.

Of course, Cheng Zihao was aware of the impression on the body.

When the forensic doctors conducted the examination back then, they also noticed this L-shaped impression.

Everyone basically thought that it was a mark formed by the suitcase used to transport the body, caused by compression.

Unexpectedly, Lu Chuan suspected that this impression was left by a steel hook used for manhole covers.

Cheng Zihao had seen such hooks used by some people when lifting manhole covers.

Indeed, only pipeline maintenance workers would use such tools.

Looking at the impression in the picture and considering the speculation shared over the phone by Qin Yong, Cheng Zihao frowned.

Back then, part of the dismembered body was discovered in the sewage canal, so the Liangzhou City Criminal Investigation Team focused on investigating the maintenance workers of that section of the canal.

The conclusion was that there were no maintenance plans near the body dumping site, and all workers at the time were questioned.

Now, it seems necessary to conduct another round of inspections.

After a bit of tidying up, Cheng Zihao informed the team leader and left the office.

The sewage canal where the body parts were found is managed by the municipal authorities, with maintenance performed by a professional construction team specializing in pipeline repairs.

Qinghe Road—Cheng Zihao visited this place three years ago and has some memory of it.

Shunfa Pipeline Maintenance.

"Who are you looking for?"

The team was located in a large yard, and as Cheng Zihao entered, he noticed plenty of materials piled up in the courtyard, along with a heap of steel hooks.

The old man guarding the gate was the same as three years ago, and Cheng Zihao had a faint impression of him: "I’m from the Municipal Bureau’s Criminal Investigation Team, here to gather some information."

As he spoke, Cheng Zihao took out his credentials and briefly showed them.

The old man hurriedly stood up, "Officer, our team leader is out today for some maintenance work. There’s not much happening in the yard; what do you need to know?"

Cheng Zihao wasn’t worried; he was here just to ease his mind.

After all, he had been here years ago and didn’t find anything.

Now, three years later, the chances of discovering something new aren’t high.

Besides, what Qin Yong provided was a hint that the mark might be left by a manhole cover hook, which was just a possibility.

After all, it was just an impression and not clearly visible.

"Sir, I want to ask about Changchun Street..."

...

Haizhou City Criminal Investigation Team, Crime Scene Laboratory.

Since the beginning of this year, the Haizhou City Criminal Investigation Team had no pending cases, although there were two from last year.

One was a theft, and the other a robbery.

Lu Chuan is currently focusing on the robbery case.

During the police investigation, they found half of the perpetrator’s face on surveillance footage.

However, half a face is not enough for facial recognition, so Lu Chuan is working on improving the clarity of the image.

Lu Chuan’s purpose isn’t to conduct facial recognition on this half-face but rather to match it within the database of prior offenders.

The scope Lu Chuan is focusing on is limited to Haizhou City, which considerably reduces the data comparison volume, and he has narrowed it down to individuals with prior robbery offenses.

From a psychological perspective, whether it’s robbery or theft, once someone engages in it, it often isn’t just a one-time affair.

Once these individuals run out of money, they tend to itch for more.

Some suspects might instinctively stick to a particular mode of crime and continue with it.

For instance, those who steal might keep on stealing, while those who rob might continue robbing.

It doesn’t mean they enjoy stealing or robbing, but the characteristics of each are different.

Thieves often need skills, whether it’s breaking into houses or pickpocketing in public places, some technical knowledge is required.

Robbery is different; it doesn’t require skills but demands precision and ruthlessness. Spot someone, rob them, and escape immediately, with familiarity with the layout being preferable.

The emphasis is on speed and surprise, catching the victim off-guard so that by the time they react, the items are already gone.

Even if they do react, the suspect can easily evade capture, achieving their goal.

Very quickly, Lu Chuan used the capabilities that came with advanced fingerprint analysis skills to enhance the details and picture quality of the half-face.

Then, he brought up all the mugshots of individuals with robbery records in a similar age range, totaling 92 images.

This number may not seem large, but it indeed isn’t small.

Across all of Haizhou City, around 500 individuals have robbery records.

These 500 individuals have accumulated over the years, among them, 90 are aged between 20 to 30, similar to the man in the video.

This age range is also a high-risk period for committing robbery.

As for the reason, Lu Chuan speculated that it might be due to financial challenges faced by individuals in this age bracket.

Upon comparison, Lu Chuan’s eyes quickly lit up with joy.

Indeed, a leopard cannot change its spots!