1995, Starting as a Criminal Investigation Expert

Inside the dissection room.

By the end of September, the weather in Nanjiang had cooled down a bit, and the dissection room, with its inherent gloom, felt even colder.

The body lay on the autopsy table.

On the shelf next to it, a yellowish, sponge-like liver was soaking in liquid.

The uterus, an organ with high fiber content and low water content, showed very little decomposition after more than two months. Examination can confirm whether the deceased had been pregnant before.

Li Shu, holding a magnifying glass, squatted beside the autopsy table, meticulously observing the deceased's adipocere right hand.

"Li Shu, you're not thinking of tracing your fingerprints, are you?"

Li Sheng, holding a lunchbox, ate and talked as he sat down.

"I'd like to."

Li Shu sighed softly, stood up, glanced at Li Sheng, and said, "Although you've been doing this for several years and are used to it, aren't you afraid that pathogens will evaporate and end up in your bowl?"

How can anyone eat that?

Anyway, Li Shu hasn't eaten much since the incident the day before yesterday.

Li Sheng shrugged and continued eating, unconcerned.

Li Shu pulled up a chair and sat down, crossing his arms and staring at the corpse's right hand.

This document from the system is going through my mind again.

Decades ago, various powders were used to target sweat-soaked fingerprints.

The most commonly used powders are gold and silver powder, as well as magnetic powder.

The magnetic powder is made by mixing carbon powder and iron powder in a certain proportion. When using it, a special magnetic fingerprint brush is used. Because of its magnetism, the powder will be attracted. When using it, gently sweep it across the surface to protect the original shape of the fingerprint to the greatest extent.

In other words, magnetic powder is now a very common method of on-site investigation.

However, using it to extract fingerprints from adipocere corpses is a method that will be explored in the future.

Li Shu carefully considered the principles behind the methods in the materials.

This method requires freezing the body first.

After being removed, as the body temperature rises, moisture and tissue fluid seep out, and the powder attached to the mastoid lines flows with the powder to the small furrows, where it settles, thus revealing the entire fingerprint pattern.

It's essentially the other way around.

This is equivalent to the difference between relief engraving and intaglio engraving.

Thinking about this, Li Shu felt that he could actually explain why he was able to come up with this method.

This can be explained using the principles of intaglio and relief engraving.

Add a little forensic knowledge, consider it a sudden inspiration, and it should be fine.

Thinking of this, Li Shu jumped up and ran out of the dissection room.

"Hey, this kid, he's such a jumpy person."

Li Sheng's hand trembled, and he almost spilled the lunchbox.

He carried the lunchbox to the dissection table and sighed, "What a pity, I don't even know who you are."

The body was brought back the day before yesterday. Including today, after two days of work, we've only confirmed that the woman was around 30 years old and had a miscarriage. There weren't any other useful discoveries.

Even the cause of death cannot be confirmed.

On the other side, Li Shu was going upstairs when he bumped into Xiao Rui leading a group of people downstairs.

"Captain Xiao, have you confirmed the identity of the deceased?" Li Shu stopped him and asked.

Li Shu didn't mention his thoughts yesterday because he was thinking that if the brigade could confirm the deceased's identity through investigation and interviews, then he wouldn't need to bring it up.

The incident occurred the day before yesterday, and a case analysis meeting was held yesterday morning to determine the direction of the investigation.

Today, a day and a night have passed, and there should be some discoveries by now.

Xiao Rui stopped and told his men to go ahead.

He was willing to talk more about Li Shu, but shook his head and said, "No, after the meeting yesterday, we checked and found that there were a total of 74 missing persons reports in Guanlin and the entire Donglin area."

"We can't confirm that the woman is around 30 years old, has had a miscarriage, has some cirrhosis, is slightly overweight, and likes to paint her nails. After screening like this, we don't find a single case that matches."

"That's why I'm planning to go to Yanling to see what's going on there."

It was a murder case, and the victim's head was sawed off, so the nature of the crime was considered heinous. Therefore, the investigation was quite intensive, and within a day, all the missing persons had been identified.

Unfortunately, based on the current conditions, there isn't even a suspected case.

The only explanation is that the deceased came from Yanling.

"By the way, did you find anything about the nail polish?" Xiao Rui asked again.

Li Shu shook his head.

The scene was constantly washed by sewage, and the body was so decomposed. The suspect had even stripped the victim of all his clothes. The only useful piece of evidence left was the nail polish.

Zhao Yongzheng is leading a team to conduct physicochemical analysis.

Li Shu asked about it in the morning, but it didn't go smoothly. It was about the most common nail polish ingredients, which he guessed were from mass-market brands, not from some high-end brands with exclusive formulas.

Xiao Rui sighed, patted Li Shu on the shoulder, said "Thank you for your hard work," and turned to leave.

During the mobilization meeting for the National Games, Tang Weidong had already requested that security patrols be strengthened during the period to prevent serious incidents from occurring.

Well, what's worse, a meeting just ended and then this murder happened.

And their heads were sawed off.

The news has already spread far and wide. It's not exactly causing panic, but the impact is still quite negative.

The discovery of a body, headless, is so cruel and terrifying.

Therefore, Tang Weidong has already taken charge of this case and instructed that it be solved as soon as possible.

The problem is, how can we solve the case if we haven't even confirmed who the deceased is?

Xiao Rui was extremely worried.

After watching Xiao Rui leave, Li Shu no longer hesitated, quickly went upstairs, and dragged Zhao Yong into Han Jianjun's office.

"Captain Han, I might have a way to extract fingerprints from the body."

Upon hearing this, the two were startled.

Zhao Yong hurriedly asked, "Li Shu, do you have any ideas?"

The surface of a corpse that has undergone adipocereification is covered with fatty acids and stearic acid formed from the saponification and hydrogenation of subcutaneous fat, making it impossible to process.

"Captain Han, look, this is what I'm thinking."

Li Shu grabbed a piece of paper and a pen from his desk and explained his method to the two of them.

"We all know that skin pores are located on the mastoid process line, not in the furrows."

Li Shu drew a cross-sectional diagram.

Then the purpose of freezing the body is explained.

When the product is removed from the freezer, moisture and tissue fluid will slowly seep out through the pores.

This is seepage, not rinsing with water. The process is slow, even, and minimal.

It only pushes the magnetic powder particles along the slope of the mastoid line into the furrow, thus creating a raised effect.

"The gaps between sweat pores along the papillary line are only 0.3 millimeters, which is about the same width as the papillary line itself. After the liquid seeps out, I think the surface tension of the liquid will destroy the magnetic powder's adsorption force, and in the end, it will not form discontinuous gaps. Moreover, even after washing, it is impossible to completely remove the surface fatty acids. They melt slightly, which will also help the magnetic powder slide off."

After Li Shu finished speaking, he looked up and asked the two of them what they thought.

Han Jianjun was getting old, and Li Shu was speaking very fast, so he couldn't keep up for a moment. He waved his hand, indicating that he needed to slow down.

Zhao Yong followed along, staring blankly at the cross-sectional diagram Li Shu drew on the paper, then his eyes suddenly lit up.

Got it!

"Damn, this method seems... to actually work."

Moreover, he suddenly understood why Li Shu wanted to use magnetic powder.

Magnetic powder is usually 300 mesh, and the particles will be larger.

Gold and silver powder, generally around 800 mesh, is lighter and finer, with stronger adhesion and greater stickiness. Once the body begins to thaw, it is more likely to stick to the bottom, making it difficult to capture clearly.

Only magnetic powder is suitable.

He became more and more excited as he thought about it, and seeing that Han Jianjun hadn't reacted yet, he eagerly explained it to him.

Han Jianjun slowly came to his senses and began to understand the principle. He pursed his lips and thought about it carefully before nodding, thinking that it might actually work.

"that is……"

Han Jianjun was still somewhat hesitant.

After all, I'd never heard of such a method before.

Also, how did Li Shu come up with this idea?

"That's right, Captain Han, I really think this method is feasible, and whether it works or not, we'll find out by trying it." Zhao Yong was eager to give it a try.

It's just freezing it and brushing it with magnetic powder. It's not like deep-frying or anything like that, so it won't damage the tissue. It's a one-time opportunity.

This method is non-invasive, and it doesn't matter if it doesn't work.

But what if it works? If the deceased happens to have fingerprints in the database, then that would solve the most difficult problem in the case.

Upon hearing this, Han Jianjun gave Li Shu a deep look and no longer hesitated.

"Then freeze it!"