civil forensic

Chapter 445
Xu Taining came to the Criminal Police Detachment by bus, it was very simple and there was no need to stop, just a pair of polished police trousers and a dusty jacket, he walked into the Criminal Police Detachment slowly.

The new policeman standing guard at the door only looked at the ID card, and quickly saluted and let the person in.

These days, plain old men in jackets are really not to be messed with.

In the meeting room of the detachment, Yu Wenshu opened a combat command room for Xu Taining. On the wall were maps and topographic maps of Changyang City. On the table was a white porcelain cup filled with green tea, with a smile on his face. The preparations are well-prepared, and a careful thought is hidden: you can save a little between your fingers, and we can also have a good 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 to a bigger map."

"Uh... a large-scale map? This one is already..."

"I mean the range of the map..." Xu Taining drew a circle in the air with his hand, and said, "This is the map of Changyang City."

Yu Wenshu thought, because we are the criminal police detachment of Changyang City.

Of course, he couldn't say that, and he still waited carefully, saying: "We are considering that the murderer's several crimes were all carried out around the scenic spots in Changyang City..."

"Your thinking is reasonable. It is indeed possible that the crime was committed around the scenic spots in Changyang City." Xu Taining nodded, and said: "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, and with a red light on, he walked along the map and said, "It's also possible to go around Changyang City's Ring Road or the Ring Expressway. of."

Yu Wenshu was numb all over.Changyang City is the capital of the province, and the road around the city is 50 kilometers long, and it will be expanded further... If this is an investigation, even if the criminal police detachment has sufficient funds, it can't help but spend so much...

The political commissar was even more terrified, afraid that Yu Wenshu would just agree, and hurriedly said: "The whole road around the city is monitored, and there are high-definition cameras at the checkpoints on and off the elevated highway for the past few years. The murderer walked here. If there is no way, it belongs to burying a hole for yourself.”

"Maybe take the bus or take a taxi?" Xu Taining asked rhetorically.

The political commissar was taken aback.Indeed, the murderer just came out to kill people. He didn't need to transport the corpse, throw it away, or bury it. He carried a nail gun with him. When he arrived at the selected place, he didn't even need to choose a place. He just found a random place and got out of the car. Climbing a mountain, going up the mountain to kill people, and returning home after killing, you don’t need to drive yourself, and public transportation makes it easier to hide your traces.

"If such a large area is drawn up, the expenses will be too high, and it is impossible for the bureau to allow us to investigate the whole city." Yu Wenshu said cautiously.

"It's normal to have limited conditions. When I do investigations, the most frequently encountered problems, the problems that I encounter almost every time, are limited conditions and limited funds..." Xu Taining said very naturally: "However, I proposed this scope. I also hope that you can understand that it is impossible to cover everything. We must assume that the murderer is also subject to some restrictions. If we do not make such assumptions, our funds will be in trouble. But if the scope of assumptions is narrowed, our investigation may not be effective. ..."

Yu Wenshu and the political commissar looked at each other and realized that Xu Taining was giving himself a vaccination.

At the same time, the two felt the fear more deeply - Xu Taining was vaccinating himself!

How much is this guy going to spend?
"This map should be changed." Xu Taining turned around in the air with the laser pointer again.

"Okay. Then what size map do you want?" Yu Wenshu's expectation value has been raised very high.

Xu Taining shook his head at this time, and said: "After you called me yesterday, I have researched this case. I think it is necessary to investigate the crime scene, or in other words, to investigate and find the murderer's path and method to enter the crime scene, etc. , are of little significance. The investment will be very large, but it may still slip through the net, which is a model that costs money and has poor results.”

Yu Wenshu remembered the range that Xu Taining had just drawn, and remained silent.

Indeed, the three cases took place in three directions on the outskirts of Changyang City, and all of them have relatively good scenery. There are parks with hills and hills, citizens who go to leisure, people who live nearby, and people who pass through the city. Considering that the roads around the city are not far away, and even the nearby villages and towns are not too far away, it is indeed suspected that it is thankless to investigate the location and route of the murder.

Furthermore, the murderer's three crimes were committed randomly, so the places where they happened may also be random.Although most of the randomness of human beings is pseudo-random, using a relatively simple analysis method, for example, draw a circle with the location of the three crimes as the center, and the intersection of the three circles may be the murderer's place of residence or work area— —However, the case analysis in reality is not so simple. There are too many prerequisites for the delineation of this range, for example, assuming that the road conditions are uniform, assuming that the murderer did not change the means of transportation, and assuming that the murderer started at the same time each time location, assuming that the murderer did not encounter any accidents on the way...

If, like foreigners, they only pursue a 50.00% homicide detection rate, such a rule is not a big problem.

But it has reached the point of inviting Xu Taining, how dare Yu Wenshu draw circles like this.

Yu Wenshu looked at Xu Taining warily.

As the saying goes, dogs can't change eating shit, and Xu Taining's way of doing things like spending money like water was not developed in a day.That is, the criminal police teams at all levels in Shannan Province got used to it step by step.

If he says it costs a lot, it may mean that it really costs a lot, but if you say he will save money, then you are delusional.

"You can check the surveillance video, but I don't think you should count on it too much. In the wilderness, the murderer only needs to wear a hat, an umbrella, and a hoodie, and our work will be for nothing." Xu Taining cut off again. a way.

Yu Wenshu nodded solemnly.

"This case, I think it will ultimately come 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 that as long as one problem is solved, the case can be solved." Xu Taining broke down the case into pieces with his fingers, and it was clear and clear.

Yu Wenshu's face unconsciously showed hope.

Xu Taining's analysis is indeed more meaningful than looking for evidence at the crime scene.

Xu Taining took a sip of tea, and said slowly: "There are quite a few people who have the ability to transform nail guns, but not many. My estimate is that there are tens of thousands of people in Changyang City and its surrounding areas..."

Yu Wenshu was taken aback: "How many thousands of people?"

Xu Taining: "Those who are engaged in the mechanical industry or electricians are all possible..."

"Wait." The political commissar said: "Even if we came to the door, how can we prove that he has modified a nail gun?"

"The three crimes were committed in the morning, two on weekdays, and one on a rest day. The three times were far away, and his alibi must be incomplete. Screen 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. If something happened, he would screen the list first. If the number of people screened out was small, he would ask specific questions. Real-person lie detectors could also be used for secret investigations.If there are too many people screened out, change the direction of screening and do cross-comparison. After narrowing down the list, go back to the first step.

Speaking of which, Xu Taining's method of solving the case is also very stupid, which is different from Jiang Yuan's and only costs more money.

Yu Wenshu missed Jiang Yuan for a moment, then took a deep breath: "Do it. Do as you say."

There was no place for him to hesitate and waste time in 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.The attitude is very good, very professional and serious, and I asked a lot of questions, some of which were prepared by professionals.

Yu Wenshu answered obediently.He is now the captain of the provincial capital, so the reporter will come here, if he is the captain, the fruit plate may come, which means the same thing, the case is solved, eat fruit, sweet, the reporter will write a report for you.If the case cannot be solved, there may not be reports, but the reports must be sent up.

Not only was Yu Wenshu secretly glad that Xu Taining was invited, so even if he died, he would die with no regrets.

……

At the same time, Jiang Yuan was also hurrying to look at the nails.

The killer in this case has already killed three people, and you can't expect a serial killer to stick to a certain schedule, even though the time between the two is variable.In particular, this kind of random killing without conflict of interest shows that he himself does not follow the social order and does not agree with the existing social moral norms.

Therefore, the murderer may start killing the fourth person at any time.

Completing the spike comparison as soon as possible is the best breakthrough Jiang Yuan has seen so far.

After the influence, participation and detection of so many cases, Jiang Yuan has gradually formed his own criminal investigation cognition.

In his view, the murderer in this case must have gone through a long period of planning, conception and design before committing the crime.This kind of serial killer is fundamentally different from ordinary people killing people.

Ordinary people kill people, on the one hand, it is limited by interests, so it has fetters and grips.On the other hand, ordinary people usually start planning and carrying out killings when their interests are greatly damaged. Moreover, planning and execution may not necessarily be carried out, usually because interests continue to be damaged, or a certain trigger point appears , he implements it.

In this way, when ordinary people kill people, they are not only involved in interests, but also limited in time, not to mention emotional impulsiveness. All of the above limit their ability to kill people, and it is difficult for them to reach the level of intelligence and physical strength. Peak condition.

Serial killers are different.The core of a serial killer is an antisocial factor. In psychological terms, there is no empathy.Ordinary people will cruelly kill ants, insects and other weak creatures when they are very young, such as two or three-year-old children, but as they grow older, they do so less and less , This is the breeding of empathy and the result of social education.

Serial killers are not like this. They have lost their ability to empathize for various reasons, so their attitude towards humans is similar to that of young children towards ants.Of course, their intelligence is normal, so they can also understand the requirements of social morality and where the boundaries of the law lie.

In order to avoid punishment and meet their inner needs, serial killers often plan to kill from a very young age, and hold them back until they are adults. They are already self-trained.

In the face of such criminals, it is absolutely impossible to use ordinary means to deal with them.

At this time, it was the police who thought of it, and they probably already thought of it—single high-end serial killers, those weak and small ones, had already been screened out when they committed the crime for the first time.

When Jiang Yuan saw the spikes, he could even imagine the murderer's pride.

The killer could have used steel balls, but instead he used ordinary spikes, which are more difficult to track, and modified a nail gun just for that.This shows that he knows very well that the "bullets" fired from the nail gun are his biggest flaws. He can take away the shell casings, the nail gun, and pay attention to footprints and fingerprints, but he can't pick the bullets and nails on the spot. , that may leave even greater hidden dangers.

However, as far as Jiang Yuan's work these two days is concerned, he feels that the murderer's time in the world is getting shorter and shorter.

If we say that at the beginning, Jiang Yuan was still worried that he could not find a suitable spike, but in the past few days, Jiang Yuan's confidence has risen.

In Jiang Yuan's view, comparing long nails and comparing fingerprints actually have something in common.

The pursuit of fingerprint comparison is actually not exactly the same.Mark the feature points, sort according to the number and similarity of the feature points, and then find the closest one among the candidate fingerprints, and eliminate the fingerprints with obvious differences...

The spike ratio is actually a feature point.

It is to choose those positions that are easy to leave traces and compare them continuously.

Now, with more than half of the nails in hand, Jiang Yuan can directly eliminate them.Many reasons for elimination don't even need to be seen with the eyes, and they can be thrown out with a shake of the weight.

This also made his progress greatly ahead of schedule.

Who would have thought that the LV6 tool trace test would have room for improvement through self-training.

(End of this chapter)