1995, Starting as a Criminal Investigation Expert

The entire family was wiped out; he was shot to death.

The body was kept in a freezer for another month, which was a heinous crime. The municipal bureau set up a special task force and investigated for three months.

The investigation records filled nine cardboard boxes.

Watching all of this would be no easy task.

Therefore, the best approach is still the same as in the previous cases involving Zhang Yichao and others: focus solely on fingerprints.

The key issue is that there are no fingerprints in this case; it's only speculated that there's a chance of obtaining them.

Then Li Shu needs to understand why such a speculation would occur.

Li Shu asked Tan Guoxiong to go find Shen Chuan and see if he was busy.

He then went to find Peng Rong.

One business aspect and one technical aspect should be enough to explain the situation of the case.

"Why don't you go and take a look? That place is still sealed off," Peng Rong suddenly suggested.

In the previous theft case in the High-tech Zone, Li Shu requested to return to the scene.

And some things are best explained when you go back to the scene.

Li Shu glanced at Shen Chuan; he had no objection.

"Then let's go."

If we could go back to the site and take a look, that would be the best.

There aren't many cars; we might need them if there's a case.

The four of them rode bicycles, huffing and puffing for more than half an hour before arriving at their destination.

Shen Chuan first went to the police station, got the door key, and then took the three people to the scene of the crime.

Only a year has passed, and everything is still the same.

In a corner of a village path, next to a large birch tree.

The old house with white walls and black tiles is built in a connected style. The small room at the back is very low and looks like an illegal structure.

The two rooms together are only about 30 square meters.

This old house has few windows, and now the front door is tightly closed with a large lock and a seal.

Shen Chuan said, "This is their old house. Huang Youjun doesn't live here; he lives in Xinding Jiayuan, which is far away. Kang Guiying lives alone; she usually lives over there."

He pointed to the end of the path and said, "There's a stall selling wontons at the intersection."

The couple came to Nanjiang in the 1950s after the founding of the People's Republic of China.

At that time, there was no household registration system. After arriving in Nanjiang, the two of them did some small business and struggled to make a living.

As if things weren't going to go wrong, Huang Youjun's father fell ill and passed away, leaving behind a widow and her two children, making life even more difficult.

Kang Guiying raised her son by selling wontons.

Tan Guoxiong looked around, puzzled, and said, "In this whole village, an old man hasn't been seen for a month, doesn't anyone find it strange?"

Li Shu nodded hurriedly.

A close neighbor is worse than a distant relative. If an elderly woman living alone is nowhere to be seen for a month, wouldn't you be suspicious?

Shen Chuan said, "Then you can only blame Huang Youjun. That guy is an old scoundrel who lends money at exorbitant interest rates. He's never been a good person since he was a kid. You could say that in this whole area, there isn't a single kid who hasn't been beaten up by him."

"At first, Kang Guiying apologized to people, but later she couldn't handle it anymore and stopped caring. When people blocked the door and cursed at her, she pretended not to hear them."

"But Huang Youjun was exceptionally filial. If anyone dared to insult his mother, he would grab a kitchen knife and fight them to the death."

"Over time, you wouldn't want to have such neighbors either. When we asked, they all said they thought Kang Guiying had been taken away by Huang Youjun."

"Huang Youjun has always wanted to take his mother away, but Kang Guiying herself is unwilling and insists on staying in this house."

Li Shu suddenly realized.

If that's the case, then it's no wonder the neighbors didn't call the police until the smell started to spread.

Shen Chuan stepped forward, tore off the seal, opened the door, and said, "Huang Youjun has complicated social relationships. Our investigation has always focused on revenge killings, but we still haven't been able to identify him."

The door opened.

The air was thick with the stench of corruption.

The house was old and covered in dust. There was no electricity, and the front window was small and covered with newspapers, making it very dark.

The front and back are essentially one open space.

A small room was partitioned off in the middle, and a loft was also built for storage.

The scene had been inspected countless times, so the group simply put on shoe covers and went straight in.

Many items were taken away as physical evidence.

However, large pieces of furniture such as cabinets and tables are still there, which can vaguely reconstruct the situation at the time of the incident.

"The freezer is inside."

Peng Rong pointed behind him and said, "Back then, we just pulled the freezer back with it. Old Qin and the others suffered a lot."

Li Shu nodded, "I can imagine it."

Go inside.

The small room at the back was essentially the kitchen, where Kang Guiying sold her wontons.

And this freezer is in the corner.

She sells fresh meat wontons, so there's naturally demand.

Shen Chuan previously said that Huang Youjun was exceptionally filial, and now it seems to be true.

Aucma freezers are not cheap.

The house looked dilapidated from the outside, but inside it had been plastered with white paint and had a cement floor. There was also a 21-inch Panda brand color TV in the corner outside.

This is the size of the room in Li Shu's house.

These facts alone are enough to prove that Huang Youjun spent a lot of money on his mother.

Shen Chuan pointed to a red-lacquered square table against the wall outside and said, "Our analysis is that the suspect arrived early, so he probably knows Kang Guiying, and Kang Guiying even invited him to stay for dinner."

"Then I used the landline at home to call Huang Youjun, which was tantamount to telling Huang Youjun, 'Your mother is in my hands.'"

"Huang Youjun is divorced. His child lives with his mother and he lives alone. He came over as soon as he received the call."

"Li Shu, look at where the mother and son fell."

Shen Chuan pointed to the area under the table.

You can still vaguely see the white lines that were drawn at that time.

They should be able to determine the location of the gunshot wound by analyzing the bloodstains.

"This means that the suspect did not ambush Huang Youjun at the door, which further proves that they knew each other and even sat down to talk after meeting."

"We speculate that Huang Youjun might have thought the suspect wouldn't kill him, which is why he came over without any precautions."

"It turned out the suspect had planned this all along and opened fire. We interviewed the neighbors, and some of them remembered that the TV was turned up quite loud, so they might have heard the gunshot, but they didn't pay attention."

Li Shu nodded, having gained a clear understanding of the case.

I crouched down and carefully examined the square table.

I did read a journal article in the system's documentation before, it was from the 1980s.

It is said that fingerprints can be revealed on wooden furniture with this type of paint when exposed to moisture.

Of course, that was a recent case, while this table in front of us has been sitting there for over a year.

The suspect also deliberately wiped the table.

"Brother Rong, where is the porcelain bowl that you think has fingerprints?" Li Shu asked.

Peng Rong led Li Shu to the kitchen and pointed to a tall cupboard in front of them, saying, "Right here."

"The incident should have occurred around 8 p.m., because the neighbors reported that the TV sound went out at that time, so the suspect may have turned it off and left the scene."

"The reason we concluded that the suspect ate here is because when we reconstructed Kang Guiying's movements that day, she went to the market in the evening and bought half a roast chicken, as well as pork belly and other dishes. Logically speaking, she couldn't have finished eating all of them by herself."

"She's getting old and usually eats very little. And Huang Youjun didn't come here that night, so the meal Kang Guiying prepared was most likely to entertain the suspect."

"You're probably thinking, since we've eaten, are there fingerprints left on the bowls?"

Li Shu nodded.

The problem is, shouldn't we wash the dishes after eating?

Peng Rong continued, "The suspect obviously knew this too, so when we arrived, the dishes were all in the cupboard, which Kang Guiying probably washed herself."

"After committing the crime, the suspect cleaned up the scene. The teacups used for drinking water were wiped clean, and he even threw away the trash at the scene."

"However, we believe that he overlooked one crucial point despite his meticulous planning."

Peng Rong stepped forward and opened the cupboard.

The kind with two layers.

"The bottom is for bowls, plates, and groceries. The top is for leftovers."

"It's empty inside now," Peng Rong explained.

"When we arrived, the leftover food on the table had long since rotted, but we could still make out that there was braised pork."

Li Shu frowned slightly; he had just eaten out last night.

"And then there's this big, thick soup bowl." Peng Rong gestured with his hands and said, "There are fish bones in it, so it should be crucian carp and tofu soup."

"Then we did an analysis and found that the suspect arrived before dinner, and Kang Guiying invited him to stay for dinner and went to the market to buy a lot of vegetables."

"She was cooking inside, and the suspect was probably standing next to her chatting."

"Is it possible that after Kang Guiying finished cooking, the suspect simply took the food and placed it on the table outside?"

"This left their fingerprints on the dishes, and then the food wasn't finished. The old man cleared the dishes, put the leftovers directly into the cupboard, and washed the other dishes."

At this point, Li Shu understood the logic behind their judgment.

Receiving the food is a subconscious action.

The suspect was aware of the need to clean up the scene, but seeing Tang Guiying washing dishes, it's entirely possible that he overlooked that detail.

This leaves fingerprints on leftover food dishes.