The Rise of the Peninsula

Chapter 183 0146 – Circumference Hypothesis
After several days of investigation, the identity of the deceased was finally confirmed. She was called Alysa (Alysa), 21 years old, a temporary worker in a local paper mill, and disappeared on the way home from the factory after the night shift on the morning of July 7. . .
Based on the results of the autopsy and the situation at the scene, the police concluded that this was a rape and homicide case, and the murderer was probably raped by blocking the road. He had no contact with Alisa before, and based on information such as corpse spots and stomach contents, the time of his death was speculated. It should be around 11 am on the 7th

In the absence of physical evidence at the scene, the police first tried to restore the scene of the incident:
The first question is because the trauma of the deceased existed in the neck, and the autopsy showed no signs of poisoning. The most reasonable guess for this situation should be: there is a method of strangling and pinching that caused the deceased to lose his resistance.

Strangulation will cause the deceased to struggle, and often leave resistance injuries, so the most reasonable guess should be:
Alisa was first strangled by the murderer from behind her neck with a rope, tightened it hard, dragged her into a coma (losing the ability to resist), and then strangled the victim to death.

In addition, the pair of sandals that appeared at the scene were confirmed by the family members of the deceased as belonging to the deceased. The strange thing is that the soles of these shoes did not have any traces of weeds at the scene. We must know that the weeds at the scene were very lush. If the deceased himself died in the grass It is impossible for such a situation to happen (the soles of the shoes will have weeds anyway), and the only reasonable explanation for this, which is also the restoration of the murderer's entire method, should be:
The deceased was strangled by the murderer on the river embankment with a white wolf on his back, and carried to the scene. During this process, the deceased struggled and his shoes fell off. After he was strangled until he lost consciousness, the murderer took him Rape and murder.

This method of killing is not very common. If the murderer can kill in this way, he should meet some basic characteristics in terms of height. For this reason, the Barron County Police Department recruited a person with a similar body shape to the deceased to carry out a special investigation. ] on-site simulation, and finally draw the conclusion
The deceased was about 155cm tall. The murderer wanted to strangle her and not let her feet drag on the ground. The murderer must be at least 20 centimeters taller than her, which means that the murderer must be at least 175cm tall and not of the same size. too weak.

Despite these conclusions, finding the murderer is still like finding a needle in a haystack. The police can only set up routine visits and investigations in the surrounding areas of the scene to find qualified men.

A month passed quickly, and the case still did not progress until an adult woman named Tina called the police on the evening of August 8 to report that she was followed by a stranger who tried to strangle her with a rope from behind. , but because her husband arrived in time, the other party ran away immediately.

This attempted case attracted the attention of the police. First of all, the place where this case occurred was less than three kilometers away from the rape and murder case - a month ago, and the method was very similar. It was regrettable because it was already late at that time. And because of insufficient lighting, the victim could not see the murderer's face clearly, and only described the murderer as "strong and tall."

Although this case provided very little information, it at least expanded the scope of investigation for the police. They combined the investigation scope of the first case and the second case. A total of 217 households within the scope were listed as investigation objects. , to understand the situation from them, what the police think is:
"Since the murderer likes to commit crimes near this place, but the body has never reappeared, could there still be potential victims who just haven't been found?"

In order to eliminate the psychological worries of the victims, the police also set up a special private contact line for the residents within the area, with the purpose of eliminating their fear of being regarded as "victims of (attempted) rape" after reporting the crime.

Their hard work and empathy paid off. In the middle of the night on August 8, an anonymous woman called and said that she had been stalked a week ago. They scratched their arms with a knife, and the two chased after each other. In the end, perhaps because a passerby appeared, the other party disappeared into the darkness.

The woman did not give the kind of evidence that would directly lead to the murderer, but she told the police one of the most critical information, that is where she was attacked:
It is located in the southeast of the first case, less than one kilometer from the factory where Alisa works.

Pu Shangyuan drew a rough map from his memory. He couldn't guarantee that the map was exactly the same, but it could be understood by a few students.

Park Sang-won held the chalk, "We need to find out the distance relationship between the incidents"

Suppose the distance between the occurrence point of the first case and the occurrence point of the second case is: d1
Suppose the distance between the occurrence point of the second case and the occurrence point of the third case is: d2
Suppose the distance between the occurrence point of the first case and the occurrence point of the third case is: d3
根据测定的: d1>d2>d3，然后擦去d2、d3，以d1为直径作圆:
The range near the center of the circle is the area with the highest psychological comfort of the criminal. This circle is the core of the circle hypothesis. Theoretically, the entire circle is the potential range of the murderer’s residence, but the possibility near the center of the circle is the most likely, which is the psychological comfort of the criminal. The area with the highest level of comfort is likely to be his residence, or his daily work.

The scope (actually nearly 200 million square meters) based on the assumption of the circumference includes several independent small farms and a fertilizer factory.

The investigation of the farm workers did not reach any conclusions, and the subsequent investigation of the chemical fertilizer factory, the police chose to conduct a selective investigation, because the first case occurred in the early morning, and it is likely that the murderer was also a night shift worker like Alisa. The cases all happened at night, indicating that the murderer had nothing to do at night. He was on day shift (or on vacation) these two days, so the police focused on investigating the shift situation of the factory, and screened the suspects based on the time when the case occurred. ,
On August 8, the qualified suspects were narrowed down to only 27 people (most of them came from a workshop). The DNA of these people was collected separately and compared with the DNA in the first case**.

On September 9, John Abel, a chemical fertilizer factory worker identified as the suspect, was arrested and sentenced to a total of 19 years in prison for murder, attempted murder, and indecent assault.

On the other hand, in the whole case, under the condition of lack of witnesses and evidence, the circle hypothesis only takes the known crime place as the condition, which greatly reduces the scope of investigation and greatly saves manpower and material resources.

"But this is a formula. I don't think it is particularly reliable, because it is a cold and fixed offensive. We cannot fall into qualitative thinking. Do you think this method is really feasible?" the student asked.

Pu Shangyuan shook his head and smiled, this is what he was waiting for, and he was afraid that they would not accept it. This formula was obtained through the efforts of all criminal geography, and it is the crystallization of everyone's wisdom. It was laughed at by others as a fixed way of thinking, so it was said If you go out, you can't be laughed to death.

"There is also a domestic case, let me introduce it to you again."

In fact, not only foreign countries, but also domestic similar cases can be referred to:
Case 2013: (2015~[-]) Daegu serial wounding case

From 2013 to 2015, a series of injury cases occurred in a city in Daegu, one of the victims died. The four cases are as follows in chronological order:
1. Case No. "2013.8.9" (Case A)
At around four o'clock in the morning, 61-year-old Zhang (female) went out for morning exercises, was followed by the murderer, beaten and raped, and finally the murderer took away all her belongings.

2. "2014" Case (Case B)
At around 77:[-] noon, [-]-year-old Yao (female) was doing farm work in her own field. The murderer passed by on a motorcycle. Long-term illness, "this disease is contagious", the murderer stopped the rape, tore off his money and gold jewelry, and fled in a car.

3. "2015.2.14" Case (Case)
At around 49:[-] p.m., a [-]-year-old Che (female) encountered a murderer riding a motorcycle on her way home. He gave up calling his family and drove away.

4. Case No. "2015.4. 17" (Case D)
At around ten o'clock in the morning, 71-year-old Zhong was found dead in the bushes next to the nursing home, with his lower body exposed.

The reasons for the combination of the four cases are as follows:
The DNA typing of case A is consistent with the DNA typing of exfoliated cells found on the plastic bottle mouth and cigarette butts found at the scene of case D.

The victims are almost all elderly, and the killers have a sexual perversion disorder similar to presbyopia.

"This murderer is quite weird, he only picks the elderly to do it." The student felt a wave of malice.

Park Shangyuan shook his head: "In the future, you will come into contact with all kinds of cases and people. There are not a few people like this, so what I want to tell you is that you must persist in your suspicion to the last step when dealing with criminals, because you don't know. We have no way of knowing whether the other party is a green monster mask with iron fangs, or a real kind person."

"Understood the teacher." Listening to the sparse applause and the very affirmative reply, Pu Shangyuan felt that he didn't move here to be a lecturer this time, which is not bad.

The victims were followed and observed secretly before being killed.

The crime scenes are located in relatively remote villages and fields.

Starting from the assumed direction of the circle:
The distance between the incident of case A and the incident of case B: d1 (21KM)
The distance between the incident of case A and the incident of case C: d2 (13KM) The distance between the incident of case A and the incident of case D: d3 (16KM)
A rough map of the comfort zone:
According to the clues provided by several survivors, the murderer was young and thin. Combined with surveillance and other analysis, it was finally confirmed that the suspect was 23-year-old Zhou. His address was within the circle and near the best comfort zone, basically in line with the crime geography. The results of scientific analysis and characterization:
Speaking of this, Park Sang-won felt his mouth was dry, so he lowered his head and swallowed a mouthful of saliva, moistened his throat, and raised his head to explain to everyone.

Here you should have a general understanding of the way of criminal geography characterization. To put it bluntly, it, like criminal psychology profiling, is a practical auxiliary technology for criminal investigation based on statistical data, and the circle hypothesis is The most basic theory of criminal geography.

"But this formula doesn't explain anything. It's too general. Do you think there is a better way for us to tell you?" The students still didn't understand, so they raised their own questions.

"Understand the Circumference Hypothesis." Park Sang-won wrote down forcefully on the blackboard with a chalk.After six characters, I threw away the pen, moistened my throat, and then began to explain to everyone.

To fully understand the circle hypothesis, two things need to be known:
1. Is there any scientific basis for the circle hypothesis? The basis for the circle hypothesis has two aspects:
Behavioral characteristics "proximity principle" and actual statistics in criminal psychology.

The so-called "proximity principle" is considered from the perspective of people's most basic environment adaptation. A person is always more accustomed to activities in an environment that he understands and is familiar with.

For criminals, most of them will not commit crimes at home, so they will deviate from their address to commit crimes, but they will not deliberately spend a lot of effort to commit crimes in an unfamiliar environment Crime, in such seemingly contradictory situations, their behavior will produce a compromise, which is manifested in the fact that the first crime they commit is within a certain range of their residence, namely:
Want to avoid your own address, acquaintances and familiar surroundings, so as not to be recognized or included in the scope of investigation by the police (deviation)
↑↓ (contradiction)
The place where the crime is committed cannot be too far from the place of residence, otherwise it will be inconvenient to escape quickly, and it is also inconvenient to destroy evidence, and the unfamiliar environment is not conducive to psychological stability. (closer)
"Neither far nor near" (compromise effect)
This compromise was studied and embodied by the British psychologist David Canter, and is the source of the circumference hypothesis.

in particular:
We assume that the murderer has a fixed place of residence. Although he really wants to commit a crime and has made up his mind, he still wants to reduce the risk of being caught as much as possible. Then we should think about it:
Where is he likely to commit his first crime?
From the perspective of a criminal, he regards the place where he committed the crime as a perfect place to succeed while minimizing danger. First of all, he is very familiar with the area where he lives and works, but he will be afraid of being caught. If someone recognizes him, he is also afraid that he will be investigated because he lives here, so it is impossible for him to commit a crime close to his home. In David's words:
Seeing that this distance is only enough to ensure safety, it is not enough to ensure avoidance of various dangers arising from unfamiliar places.

After the first crime, he may be aware of the threat this poses to him. If he still commits the crime at an optimum distance, then this area may not be so safe. First of all, the people there may become Be vigilant, it is no longer the "pollution-free area" before, so he will choose the crime location in different directions, and lengthen his own moderate distance, which is the second crime location.

(End of this chapter)