1995, Starting as a Criminal Investigation Expert

Chapter 116 The Inspiration from the Zhou Pan Case

One.

Liu Weikun led his team to upgrade the system.

She couldn't help but grumble a bit, and then, prying open her eyelids, showed Li Shu how red her eyes were.

"And look at those dark circles under your eyes."

At Shi Qingyun's age, she no longer cares about specific work.

Li Shu only mentioned his ideas.

It's a classic case of those above just talking, while those below are running themselves ragged.

These past few days, he has practically lived at the school, writing code day and night.

"Thank you for your hard work."

Li Shu quickly smiled apologetically and said, "How about this, I'll treat you to dinner today. You choose the place, and I'll just pay."

Liu Weikun scoffed, "Forget it, if anyone's going to treat, it'll be me."

When Li Shu came to Anjing, he was the true master.

"By the way, how's your computer science coming along? Don't tell me you still only know how to play Super Mario." Liu Weikun asked in a tone as if checking homework.

At least I taught Li Shu what books to buy and how to learn programming.

He's a disciple of my lineage, right? If all he can do is play Super Mario, wouldn't he be a disgrace to the sect when he's out and about?

"How is that possible?"

Li Shu quickly shook his head and said, "I can write programs already."

Liu Weikun's eyes lit up, thinking to himself, "Wow, that's impressive! It hasn't been that long."

He asked what kind of programs he could write.

Li Shu's tone became somewhat weak: "I can write a+b and a—b, especially a—b, I can even write a judgment statement."

Liu Weikun rolled his eyes so hard they almost reached Shanhaiguan, then gave him a thumbs up and said, "You really know a lot."

Li Shu was just joking; the real issue is that programming is really not easy to learn.

Liu Weikun said, "It's a pity you didn't plan to stay in Anjing, otherwise I could help you get a self-study exam spot at the computing center. You won't have a student status, but you can still study."

He heard that Li Shu had obtained a correspondence course offer from the Public University and had no intention of staying in Beijing.

He added, "Here's what we'll do: when you leave, I'll get you some materials. You can study them on your own when you get back, and ask me if you don't understand anything."

Li Shu thanked him, feeling deeply moved.

I came to Anjing, and putting the case aside, I did get to know a bunch of big shots and come into contact with some top-tier resources.

Before, when I was in Nanjiang, it was difficult to buy any computer-related books.

If you know someone there, you can directly access Peking University's study materials.

After chatting for a while, the system upgrade was completed.

Liu Weikun first explained to Li Shu how to operate the modified software before making way for him.

Li Shu opened his notebook and, following the organized "descriptions," began to divide the five fingerprints into zones.

The accuracy rating system we developed was to find the best description to facilitate the current multi-finger joint comparison.

First, compare all five fingers together.

The comparison did indeed consume more computing power, and it took a long time for the results to appear.

Li Shu quickly clicked on the optimal result.

"It doesn't seem like it."

Wang Ze'an, who was standing closer, glanced at the objects and frowned.

Tan Ligang was also there, standing behind silently watching, his brows furrowed as well.

He still felt that Li Shu's fingerprint extraction and comparison technology was already at the top level in China.

The technology itself is no longer the problem.

The reason it didn't match was because the suspect had no criminal record.

"Don't rush."

Li Shu tried making some minor adjustments and running the test a few more times.

After running it five times in a row, it still didn't work.

However, Li Shu did not stop. According to the plan, he cut off one finger and compared it with four fingers.

With fewer fingers compared, the comparison range is expanded, which may increase the chances of finding the correct result.

Each time, reduce the number of different fingers, and then run five rounds of each.

Unfortunately, after 25 rounds of testing, they still couldn't find a match.

At this point, Wang Ze'an began to sigh deeply and remained silent.

Li Shu gritted his teeth, cut off another finger, combined them into threes, and continued running.

More combinations, more time-consuming.

I worked on it until dark, my eyes were sore and tears were streaming down my face from staring at the screen, but I still got nowhere.

"Alright."

Liu Weikun stopped Li Shu, who was about to continue running the results in pairs, and said, "Even I, a layman, can see that it won't work. There's no way you can match it with the stock. No matter how you adjust it, it won't match."

Then Tan Ligang patted Li Shu on the shoulder and said, "That's right, Li Shu, you've done your best. Let's stop here. Also, although we didn't match the fingerprints, at least we got the suspect's fingerprints, which is already a huge breakthrough."

If we don't match them now, we will eventually match them in the future and catch this person sooner or later.

"But----"

Li Shu understood the reasoning, but when he thought of Tao Xingrun and Lele, he just couldn't accept it.

Moreover, everyone had cooperated so well when he came to Anjing. They had all worked hard together to get to this point, but they didn't match up. Li Shu felt really frustrated and upset.

"Why don't we try again? Besides, the ministry still has a lot of paper files, maybe they're in there."

The department has nearly ten million fingerprint records, but the system has only entered one-fifth of them from the nearest location, so there is still a chance.

"Alright, Li Shu."

Wang Ze'an also spoke up, advising, "You were always pessimistic before, worried that the comparison wouldn't work, so you thought about making a probability model. Don't be discouraged, we still have a chance."

Li Shu sighed softly. It wasn't that he was discouraged, but rather that he had worked so hard for so long and invested so much energy, only to have it all come to nothing. It was a little hard to accept.

"I'm fine."

Li Shu stood up and asked about the situation on Geng Zheng's side.

It's been a week since the idea was proposed, the project was immediately launched, and a team was organized to conduct the investigation. I don't know how it's progressing.

Wang Ze'an said, "It'll be soon. I asked Professor Geng yesterday, and he said he already has an idea and is considering how to implement it. I'll go to Peking University and urge him on."

Li Shu immediately said, "Then I'll go too."

Tan Ligang then returned to the station to report the situation to Liu Yaoqing.

"Ugh."

Liu Yaoqing sighed softly and said, "As expected."

He didn't seem too disappointed.

When the initial comparison failed, he already had a hunch that the suspect was most likely not in the database and had no criminal record.

After telling Tan Ligang to go back first, Liu Yaoqing called Liu Xinfeng and explained the situation.

On the phone, Liu Xinfeng was silent for a moment before saying, "Old Liu, please talk to Li Shu. He's still young and has solved many major cases before. This time he's encountered some setbacks. Don't let it affect his mentality. You need to let him know that not being able to match the target has nothing to do with his ability."

It's not that people lack ability; it's just that fingerprint matching has its limitations. If there's no record in the database, then it can't be matched.

"I know."

Liu Yaoqing knew what was going on and said, "Xiao Liu, although there was no match, I think there's still a chance for this case to turn around."

Across from him, Liu Xinfeng asked, "Mr. Liu, are you referring to the probability model that Li Shu worked on?"

Liu Yaoqing said, "That's right, his idea is excellent, and I think the chances are very high. If we can actually deduce the suspect's residence through this probability model, then with fingerprints and a sketch in hand, and by organizing manpower for a large-scale search, I think we should be able to find this person."

Liu Xinfeng, sitting opposite him, was lost in thought.

He had heard about the probability model; after all, a research project had to be approved by the ministry.

What Liu Yaoqing said was consistent with his judgment.

If we can deduce which county or city has the highest probability, it's much easier than searching aimlessly.

"Okay, let's wait for the results from the probability model before making any decisions."

Liu Xinfeng nodded, then chuckled and teased, "With these two top experts working together, they should be able to catch the person by now."

Li Shu alone is at the expert level.

Zhang Xin helped with the portrait.

Unfortunately, even the seemingly invincible Zhang Xin suffered a setback in this case.

The victims' situations are indeed very complicated.

They have poor descriptive abilities, and their descriptions become even more inaccurate after being frightened.

In addition, the suspect's deliberate disguise made it impossible to determine whether he was wearing glasses, resulting in a less than satisfactory final portrait.

Liu Yaoqing chuckled and said, "That's right, this person is Sun Wukong, ugh, he's a demon and monster, it's time to catch him."

Meanwhile, Li Shu followed Wang Ze'an to Peking University.

When they found Geng Zheng, they were surprised to find Yang Shaoting there as well.

Upon seeing the two people, his eyes lit up, and he hurriedly asked about the fingerprint comparison results.

Li Shu shook his head slightly.

A hint of sadness flashed in Yang Shaoting's eyes, but he quickly adjusted his mindset and said, "It's okay, there's still hope, Li Shu. The more I get to know you, the more interesting your probability model seems. It's much more accurate than what they said before, just drawing a few circles."

He glanced at Wang Ze'an.

The Second Institute had come to the Bureau to promote it before, and I thought it was some profound theory, but it turned out to be just drawing a few circles.

Unlike Li Shu's, which at least involved calculation, this seems much more reliable.

Wang Ze'an instinctively wanted to refute, but he swallowed the words back.

I didn't know Li Shu's probability model, but now that I do, I feel that the determination of the center of the circle was too hasty.

"Professor Geng, please hurry up here," Yang Shaoting said, turning his head.

Geng Zheng stood in front of the blackboard and said somewhat helplessly, "If you want to talk, go outside and do it. Don't bother me. This matter can't be rushed."

Yang Shaoting led the two men to the door, offered Wang Ze'an a cigarette, and then said, "Li Shu, don't think too much about it. Solving a case is never smooth sailing. At least we know this bastard's fingerprints now."

Once we find him, we can nail him to the ground.

Li Shu understood this point and thought for a moment before saying, "The key is that even if the model does pinpoint the location, it won't be easy to find the person if they don't have a criminal record."

The county or city with the highest probability of being identified has a much smaller population, but it is still in the hundreds of thousands or millions.

Collecting fingerprints from all eligible men in the city is no easy task.

Therefore, Li Shu considered that he should continue to find ways to screen the target audience.

"Director Yang, we handled a case a while ago. Could you listen to it and see if it has any reference value?"

Li recounted Zhou Pan's taxi robbery case.

The method used to find Zhou Pan at that time also inspired the method used to find Zheng Cheng later.

The current situation is similar: we know the fingerprints, but the suspect has no criminal record, and we need to find him.

After hearing this, Wang Ze'an was surprised and said in astonishment, "You guys are really amazing. The suspect only touched the victim once, and you were able to analyze that he was a guy who liked to visit prostitutes."

Li Shu smiled and said, "I was lucky to actually find him."

Yang Shaoting, standing beside him, stubbed out his cigarette, frowned, and thought for a while before saying, "Li Shu, the case you mentioned has really given me some inspiration."

He organized his thoughts and then said, "You see, this case started in the first half of 93. In 94, we began to shift our investigation focus, suspecting that this person was not a local of Anjing, but had migrated from other counties or cities."

"At the end of the year, Zhang Xin from Matsuura came over and helped make a forensic portrait. Although it didn't look like him, at least it gave us a direction."

"We arranged for people to stake out the area around the school and at major transportation hubs with sketches, because we also considered that the suspect was unlikely to have entered Beijing by bicycle, and would have mainly relied on public transportation."

"This timeframe was roughly before the Lunar New Year this year. This bastard was quiet for a while during the Lunar New Year, but after the Lunar New Year, he committed eight more crimes."

He paused briefly before beginning to explain his thought process.

"Our strategy at the time was to use both overt and covert methods, with shifts for surveillance and fixed-shift checks. For suspicious individuals within a certain age range, we would check their ID cards and register their information."

"This includes registering passengers traveling to Beijing by public transportation, such as trains and long-distance buses."

"It hasn't stopped yet. Although we haven't found any results, we've accumulated a lot of identity information. Is it possible that we found this person back then, but he had a strong mentality and managed to cover it up without us noticing?"

"After all, he committed another crime after we started staking out the area, which means he must have been to Anjing. Now we're doing probability modeling. If we analyze which county or city the suspect is most likely to be in, can we start our investigation from that information?"

"Just like Li Shu said, we'll collect fingerprints door-to-door, one by one. That's much less work than collecting fingerprints from the entire county or city."

Li Shu nodded hurriedly, thinking it was feasible.

Simply collecting fingerprints from men in a county or city is still a clumsy method, like looking for a needle in a haystack, and the workload is definitely not low.

Yang Shaoting's eyes lit up as he thought about it. He turned and rushed back into the room, urging Geng Zheng to hurry up.

"Don't rush me, it's fast enough already."

Geng Zheng, without even looking up, said that he also felt the pressure.

Since Yang Shaoting had thought of this, he didn't just sit idly by waiting for Geng Zheng to give his results.

He immediately made arrangements, the first being to organize the previous registration information.

At the same time, people were directly assigned to conduct mandatory fingerprint collection on all men aged 20 to 40 who were coming to Beijing, from other places, or from surrounding counties and cities, starting with public transportation.

The collected fingerprint cards are sent directly to the First and Second Institutes.

Then Li Shu won't have to wait idly anymore; he can compare each batch as it arrives.

Unfortunately, the search is still aimless and widespread. To save manpower and resources, we still have to wait for Geng Zheng to provide results.

Feeling the pressure, Geng Zheng also began working overtime.

Finally, three more days passed, and on November 10th, Geng Zheng finally got the results.

He first called the Second Institute.

Upon learning the results, Wang Ze'an rushed into Li Shu's room, pounded on the door, and excitedly exclaimed, "Professor Geng has finished calculating!"

Li Shu, engrossed in the densely packed fingerprint collection cards, hurriedly looked up to ask what the results were.

Which place?

Wang Ze'an looked excited: "Langfang and Anci have the highest probability."