Xu Taining came to the Criminal Police Detachment by bus. It felt very simple, and there was no need to stop. He only had a pair of polished police trousers and a dusty jacket, and walked slowly into the Criminal Police Detachment.
The new police officer standing guard at the door only looked at the ID and quickly saluted and let the person in.
These days, you really don't dare to mess with a simple old man wearing a jacket.
Yu Wenshu opened a combat command room for Xu Taining in the detachment's conference room. Maps and topographic maps of Changyang City were hung on the wall. A white porcelain cup was placed on the table with green tea brewed in it, with a smile on his face.
The preparations are thorough, and there is a small thought hidden in it: if you save a little between your fingers, we can also have a prosperous New Year.
Xu Taining smiled back at Yu Wenshu, picked up the green tea, looked at the map, and said: "If you want to put a map, it's best to change it to a bigger map."
"Uh...a large-scale map? This is already..."
"I mean the map range..." Xu Taining drew a circle in the air with his hand and said, "This is the map of Changyang City."
Yu Wenshu thought to himself, because we are the Changyang City Criminal Police Detachment.
Of course, he couldn't say that, but he still waited carefully and said: "We are considering that the murderer committed several crimes around the scenic spots in Changyang City..."
"What you are thinking makes sense. It is indeed possible that the crime was committed around the scenic spots in Changyang City." Xu Taining nodded and added: "But it is also possible that the crime was committed around the scenic spots around Changyang City, or...
"
Xu Taining took out a laser pointer from his old jacket, flashed a red light, and walked along the map and said: "It is also possible to go around the ring road in Changyang City, or the ring expressway.
of."
Yu Wenshu's whole body felt numb. Changyang City is the provincial capital, and the ring road is 50 kilometers long. If it is expanded further... If this is an investigation, even if the criminal police detachment has ample funds, it can't help but spend so much...
The political commissar was even more frightened when he heard this. He was afraid that Yu Wenshu would just agree to it, so he quickly said: "The entire ring road is monitored. There are high-definition cameras at the top and bottom of the elevated highway. In recent years, the murderer walked here.
If you don’t follow the road, you’re digging a hole for yourself.”
"Maybe take a bus or take a taxi?" Xu Taining asked back.
The political commissar was stunned when he heard this. Indeed, the murderer just came out to kill people. There was no need to transport the body, throw it away, or cut it into pieces and bury it. He carried a nail gun with him, and when he arrived at the chosen place, he didn't even have to choose, just randomly.
Find a place, get off the car and climb the mountain, go up the mountain to kill people, and go home after the killing. You don't need to drive yourself. Public transportation makes it easier to hide traces.
"If we draw such a large area, the expenditure will be too high, and the bureau will not allow us to inspect the entire city." Yu Wenshu said cautiously.
"It's normal to have limited conditions. When I do investigation, the most common problem I encounter, the problem I encounter almost every time, is the limited conditions and funding restrictions..." Xu Taining said naturally: "However, I proposed this scope,
I also hope you can understand that it is impossible to cover everything. We must assume that the murderer is also subject to certain restrictions. If we do not make such assumptions, our funding will be problematic. But if the scope of the assumption is too small, our investigation may not be effective.
…”
Yu Wenshu and the political commissar looked at each other and realized that Xu Taining was inoculating himself.
At the same time, the two of them felt their fear more deeply - Xu Taining was inoculating himself!
How much is this guy prepared to spend?
"Let's change this map." Xu Taining turned the laser pointer in the air again.
"Okay. Then how big a map do you want?" Yu Wenshu's expectations were already very high.
Xu Taining shook his head at this time and said: "After you called me yesterday, I studied the case. I think that the crime scene should be investigated, or in other words, the way to find the murderer's entry into the crime scene, etc.
, are of little significance. The investment will be very large, but it may still slip through the net. It is a model that costs money and has poor results.”
Yu Wenshu thought of the area Xu Taining had just painted and was speechless.
Indeed, the three cases occurred in three directions on the outskirts of Changyang City, and they were all parks with relatively beautiful scenery, including hills and hills. Citizens who went there for leisure included people living nearby and people passing through the city.
Considering that the ring road is not far away, and even the nearby towns and villages are not far away, investigating the location and path of the murder is indeed a thankless task.
Furthermore, the murderer's three crimes were committed randomly, and the locations where they occurred may also be random. Although most human randomness is pseudo-random, using a relatively simple analysis method, for example, draw a circle with the three crime locations as the center.
, the intersection of three circles may be the murderer's residence or work scope - however, the analysis of the case in reality cannot be so simple. There are too many prerequisites for the delineation of this scope, such as assuming roads.
The conditions are uniform. It is assumed that the murderer does not change means of transportation, that the murderer starts from the same place every time, and that the murderer does not encounter any unexpected situations on the way...
If, like foreigners, you only pursue a 50% homicide detection rate, this demarcation is not a big problem.
But it has reached the point of inviting Xu Taining, how dare Yu Wenshu draw such a circle.
Yu Wenshu looked at Xu Taining warily.
As the saying goes, dogs can't change their ways of eating shit, and Xu Taining's way of spending money like water was not learned in a day. It was learned step by step by the criminal police teams at all levels in Shannan Province.
If he says he spends a lot of money, he may really spend a lot of money, but if you say he will save money, you are just thinking blindly.
"You can check the surveillance video, but I don't think you should rely too much on it. In the wilderness, the murderer only needs to wear a hat, an umbrella, and a hoodie, and all our work will be in vain." Xu Taining cut off again.
There is a way.
Yu Wenshu nodded solemnly.
"In this case, I think it ultimately comes down to the weapon. Because the most special thing about this case is the weapon. A modified nail gun. Where did the nail gun come from? Where was it modified? Who modified it? These three
I think as long as one problem is solved, the case can be solved." Xu Taining used his fingers to break down the case into pieces and make it clear and clear.
Yu Wenshu's face showed hope unconsciously.
Xu Taining's analysis is indeed much more meaningful than finding evidence at a crime scene.
Xu Taining took a sip of tea and said slowly: "There are many people who have the ability to modify nail guns, but in fact there are not many. I estimate that there are tens of thousands of people in Changyang City and surrounding areas..."
Yu Wenshu was stunned: "Tens of thousands of people?"
Xu Taining: "Those who are engaged in the machinery industry and those who are electricians may..."
"Wait a minute." The political commissar said, "Even if we come to him, how can we prove that he has modified a nail gun?"
"The three crimes were committed in the morning, twice on working days, and once on a rest day. The three times were very far away, so his alibi must be incomplete. Filter out the list and look at it again
Is there any way to further screen?" Xu Taining answered quickly.
Yu Wenshu knew that Xu Taining's working mode was like this. When he was in doubt, he would first screen the list. If the number of people screened out was small, he would ask specific questions, use real-person polygraph testing, or conduct secret investigations. If there were too many people screened out, he would change to another one.
After directional screening, cross comparison, and narrowing down the list, go back to the first step.
Speaking of which, Xu Taining's method of solving crimes is also very stupid. It is different from Jiang Yuan's stupid method, and it is more expensive.
Yu Wenshu missed Jiang Yuan for a moment, then took a deep breath: "Do it. Do as you say."
There was no room for him to hesitate and waste any more time on this case.
Afternoon.
While Xu Taining was still preparing, a reporter from Changyang Evening News came to the Criminal Police Detachment.
The reporter was called by the director. His attitude was very good, very professional and serious, and he asked a lot of questions. Some of them seemed to have been prepared by professionals.
Yu Wenshu answered obediently. He is now the detachment leader of the provincial capital, so the reporters are here. If he were still the captain, he might be the fruit plate. The meaning is the same. The case is solved, eat the fruit, sweet and sweet.
, the reporter will write a report for you. If the case cannot be solved, there may not be a report, but the report will definitely be sent to you.
Not only was Yu Wenshu secretly glad, but he also invited Xu Taining. In this way, even if he died, he would die without any regrets.
…
At the same time, Jiang Yuan was also seizing the time to look at the nails.
The murderer in this case has killed three people. Although the time between the two is uncertain, you cannot expect a serial killer to abide by a certain schedule. Especially this kind of random killing without conflict of interest shows that he does not follow society.
Order and do not agree with the existing social moral norms.
Therefore, the murderer may start killing the fourth person at any time.
Completing the long nail comparison as soon as possible is the best breakthrough Jiang Yuan has seen so far.
After being influenced by, participating in and solving so many cases, Jiang Yuan has gradually formed his own understanding of criminal investigation.
In his opinion, the murderer in this case must have planned, imagined and designed for a long time before committing the crime. This kind of serial killer is fundamentally different from ordinary people who kill.
Ordinary people kill people. On the one hand, they are limited by interests, so they have fetters and grips. On the other hand, ordinary people usually start planning and implementing murders when their interests are greatly damaged. Moreover,
Planning does not necessarily lead to implementation. Usually, he will only implement it when his interests continue to be damaged or a certain trigger point occurs.
As a result, when ordinary people kill people, they are involved in interests, time constraints, and not to mention emotional impulses. All of the above make them restricted in the matter of killing, making it difficult for them to reach the limits of intelligence and physical strength.
Peak state.
Serial killers are different. The core of serial killers is antisocial factors. In psychological terms, they have no ability to empathize. Ordinary people will be cruel at a very young age, such as two or three years old.
They do not hesitate to kill ants, insects and other weak creatures, but as they grow older, they do so less and less. This is the development of empathy and the result of social education.
Serial killers are not like this. They have lost their ability to empathize for various reasons. Therefore, their attitude towards humans is similar to that of young children towards ants. Of course, their intelligence is normal, so they can also understand society.
Moral requirements and legal boundaries.
In order to avoid punishment and satisfy their inner needs at the same time, serial killers often plan to kill from a very young age and hold back until they are adults. They have already trained themselves.
Facing such criminals, it is definitely not possible to use ordinary methods to deal with them.
At this time, it was the police who thought of it, and they probably already thought of it - only high-end serial killers, those who are weak and small, have been screened out when they commit crimes for the first time.
When Jiang Yuan saw the spike, he could even imagine the murderer's pride.
The murderer could have used steel balls, but he still used ordinary long nails that are harder to track, and specially modified a nail gun for this purpose. This shows that he knew very well that the "bullets" fired from the nail gun were his biggest flaw
, he can take away the bullet casings, take away the nail gun, and pay attention to footprints and fingerprints, but he cannot pick out bullets or long nails on the spot, which may leave greater hidden dangers.
However, based on Jiang Yuan's work these two days, he felt that the murderer's time in the world was getting shorter and shorter.
If at the beginning, Jiang Yuan was worried about not being able to find suitable spikes, over the past few days, Jiang Yuan's confidence has increased.
In Jiang Yuan's view, comparing long nails and comparing fingerprints actually have something in common.
What fingerprint comparison pursues is actually not exactly the same. Mark the feature points, sort them according to the number and similarity of the feature points, and then find the closest ones among the candidate fingerprints, and eliminate the fingerprints that are obviously different.
…
The ratio of long nails is actually a characteristic point.
Just choose those locations that are easy to leave traces and compare them constantly.
Now, with more than half of the nails in his hands, Jiang Yuan can eliminate them directly. Many of the reasons for elimination can be thrown out without even looking at them with his eyes.
This also made his progress greatly advance.
Who would have thought that LV6’s tool mark inspection would have room for improvement due to self-training.
