1995, Starting as a Criminal Investigation Expert

I knew it! There's no need for someone to travel all this way to urge me to update.

"Editor Wang, what case is it?" Li Shu asked.

The Fifth Bureau of the Ministry is responsible for investigating major cases at the national level.

The Second Research Institute focuses on physical evidence identification research.

Their relationship with the Fifth Bureau is essentially the same as that between the detachment and the technical brigade.

Therefore, a case that the Second Research Institute takes seriously must not be a small case.

Wang Ze'an didn't say what case it was, but said as they walked, "Let me tell you something. It's about a 28-inch bicycle, you know, the handlebar grips."

Li Shu nodded.

Wang Ze'an continued, "This case is black. To increase friction and texture, we used multi-band light sources to illuminate it, but the effect wasn't good. However, we speculate that there must be latent blood fingerprints on it. In a dark room, with side lighting, you can see a little bit of them."

He mentioned multi-band light sources.

Li Shu learned about this from 803, who said that the Second Research Institute had developed domestically produced equipment last year, which replaced imported products.

As for Wang Ze'an saying the effect was not good, that's normal.

As Zhou Xuewen explained, normally, under 415-nanometer ultraviolet light, hemoglobin has a strong absorption peak, which can be observed with the naked eye as a blood fingerprint.

However, under ultraviolet light, blood appears dark brown and is clearly visible on light-colored surfaces. But on a black object like a mask, the effect is definitely not good; it's just black on black, so naturally, it's not visible.

Only by using staining agents to first stimulate the fluorescent properties of proteins can they be observed.

When he said that, Li Shu understood.

Clearly, this was because he had heard about the EOS dye during the phone call earlier, which led him to think of applying it to this case.

Because the conditions are similar, both are dark-colored objects.

"There's a problem."

Li Shu suddenly thought of something: "If it's a Phoenix Forever brand, and the grip is made of rubber, blood would probably seep through, affecting the display."

Vulcanized rubber may look dense, but it is actually porous at the microscopic level and can be slightly permeated by blood.

Wang Ze'an nodded to himself.

I thought to myself that talking to smart people is so easy, because they can notice things that others don't.

"It's not made of rubber. As you know, rubber ages easily, so we replaced the handlebar grips on this car with PVC plastic ones. This is the main reason why we firmly believe that we can extract latent fingerprints from it."

Rubber is soft and has good anti-slip properties, but it is slightly more expensive.

After prolonged use, when it becomes sticky due to aging, it can be replaced.

Some people will switch to PVC grips, which are soft plastic. Although they are hard and slippery when sweaty, they are cheap.

"If that's the case, there shouldn't be any problem."

This type of grip is made of plastic, which is a non-permeable material, similar to the case of Zhou Pan.

At this point, Li Shu thought of something else and quickly asked how long the physical evidence had been there.

EOS staining is very effective for old fingerprints, but proteins will eventually degrade, unlike vacuum coating technology, which targets deposited inorganic salts and can reveal them no matter how long they have been there.

According to the data from the system, based on the rate of protein degradation, the effect becomes very poor after six months.

Upon hearing Li Shuyi's question, Wang Ze'an secretly thought that coming here was indeed the right decision.

Some issues can only be clarified by face-to-face communication.

"It's been almost four months, is it okay?" He asked, his voice slightly tense.

Li Shu breathed a sigh of relief and said, "That's alright. Although the effect will be weaker using my method, it should still be fine."

Wang Ze'an was overjoyed and quickly said, "Great! When do we set off? How about tomorrow?"

Ugh?

Li Shu was taken aback. Set off for Anjing?

"This solution isn't complicated to prepare, can't you make it yourselves?" Li Shu asked rhetorically.

The operation is not difficult, not to mention that the Second Research Institute has multi-band light sources, which is much better than the conditions of the Nanjiang Municipal Bureau.

Wang Ze'an quickly shook his head: "We've never done this before. If we do it wrong and something goes wrong, we'll be in big trouble."

Li Shuxin said, "Then you can try it out first, and then get familiar with the process before collecting physical evidence."

"This...is the main reason..."

For a moment, Li Shu didn't know what to say.

He suddenly came over, explained the situation, and then suddenly wanted me to go to Anjing.

We were completely unprepared.

To this day, he doesn't even know what case it is.

Wang Ze'an realized what was going on and said, "You're worried about the work at the Municipal Bureau, right? Could you ask someone else to do it for you? Also, I can talk to your bureau chief. It should be fine. Just treat it as a business trip. You can also take a trip to Anjing."

Li Shu had never been to Anjing, nor had he ever paid homage to Tiananmen Square.

But the key point is that this happened too suddenly.

"Researcher Wang, may I ask what kind of case it is?"

It must be a big case, but I haven't heard much about it.

After all, it's the capital city. If a major case were to occur, it would be reported.

Having already extended the invitation, Wang Ze'an had no reason to hide the truth any longer. A flash of anger crossed his eyes as he gritted his teeth and said, "He's a beast."

Qian Rui and the others were looking at the crime scene when Wang Ze'an stopped, leaned against the wall, and took out a pack of cigarettes, offering one to Li Shu.

Li Shu shook his head.

He lit one himself, took a deep breath, and said in a deep voice, "Around the first half of 93, there was a beast in the Anjing area who specifically stalked little girls."

"Sometimes he uses sweet talk, like pretending to be a gas inspector to trick people into opening the door, and once inside..."

He stopped there, his eyes filled with boundless anger.

Li Shu's heart skipped a beat, and he exclaimed in surprise, "He can't?"

Targeting little girls specifically, could it be...?

Wang Ze'an nodded slightly.

Li Shu gasped and cursed, "Damn, that's worse than an animal."

Wang Ze'an forced a smile at Li Shu's righteous indignation and continued, "He not only violated the victims, but also committed burglary. Most importantly, it wasn't just one or two incidents."

Li Shu was shocked. It wasn't just one or two cases; it was several.

Are there many cases?

Wang Ze'an nodded and said, "It's been a little over two years now, and a total of 43 cases have occurred."

"How many?"

Li Shu's eyes widened in disbelief.

Are you kidding me? Starting at 43!

The suspects targeted little girls, which means...

Li Shu gasped, then asked, "So you didn't catch him?"

We have to search the whole city to find that beast.

Moreover, with so many cases and all eyewitnesses, they should know the person's physical characteristics, so it should be easy to find them.

Wang Ze'an shook his head slightly and sighed, "Kids have very weak resistance. And this bastard is very selective in his targets; he usually targets those who wear keys around their necks."

He pointed to his neck.

Children often lose their house keys, so many adults will put a string on them and hang them around their necks.

"If you hang a key on your phone, it shows to some extent that you are capable of walking home and opening the door by yourself after school. But if he follows you, he will screen you again."

"They target children who don't have grandparents and whose families are both working. Because when both parents work, the adults aren't home when the children get out of school, giving the suspects an opportunity to commit crimes."

"He would run away as soon as he finished, and he would even use whatever was available to tie up the child. By the time the adults at home came home from get off work, it was too late to find him."

Li Shu fell silent.

If Wang Ze'an's description is accurate, then it would indeed be difficult to catch him immediately.

The worst part is that this bastard is absolutely insane. In two years, there have been 43 cases, which is an average of one every two weeks.