Chapter 1144: They Are Different

"Geographical portrait? Criminal geography and environmental criminology? You say this, I won't be sleepy." Liu Jinghui became excited immediately: "Chicago School's crime analysis, I am also relatively interested. By the way, you said that using theory for related practice, I have really done similar cases."

Jiang Yuan said while walking: "Oh, have you done similar cases?"

"Of course. Before you, some cases without clues, really can only draw circles to visit, etc. At that time, I was making judgments based on crime pattern theory..."

"Is it useful?" Jiang Yuan didn't really want to discuss this purely theoretical topic, but he was indeed a little curious.

"Useful. For example, crime pattern theory believes that the spatiotemporal interaction of crime elements makes crime most likely to occur in areas where the activity spaces of potential criminals and potential victims overlap. I caught a serial rapist using this method years ago, marking all the activity areas of the victims, and then looking at whether the suspect has activity areas that intersect with all these victims..."

Jiang Yuan interrupted Liu Jinghui's eloquence: "Is it easy to do?"

Liu Jinghui was stunned for a moment, and then entered the state of memory. After a good while, he said: "Determining the range is to investigate and visit, and finally caught the criminal... It is certainly not easy to do. I used to do investigations, but I didn't have your support."

Geographical portrait, environmental criminology, etc., are all theoretical studies of crime based on geographical factors. Further development includes crime pattern theory, routine activity theory, rational choice theory, and crime space theory, etc.

These theoretical things, when facing some small cases, actually have no use. Because small cases can not be solved. If you really can't find clues, giving up is it.

Most police officers only use these theories that deviate from intuition when they encounter big cases that must be solved, treating a dead horse as a living horse doctor.

And for foreign aid like Liu Jinghui, even if he fights under the name of a higher-level unit, using these crime theories to solve cases will still be regarded as a scholar. The cooperation of various units has to be neglected. If the task is too heavy, there are those who say strange things to your face, and things are not going well, etc., I think it is also a common occurrence.

Jiang Yuan nodded, half understanding.

Liu Jinghui looked at his own dragon's ignorant appearance and couldn't help but sigh: "People cannot imagine things they have never seen!"

"Geography's restriction on people is indeed very large. People are prisoners of geography." Jiang Yuan nodded in agreement. Northerners who have never seen the sea can hardly imagine the surging waves of a typhoon day, and Southerners who have never seen snow can hardly imagine the cold of splashing water into ice.

Liu Jinghui shook his head: "I'm talking about handling cases. When we are doing cases outside, sometimes the things we encounter, I'm afraid you can't even imagine... For example, you who have a ranch at home, can't imagine that some people will do strange things for a smoked chicken."

Jiang Yuan looked at Liu Jinghui sympathetically and curiously.

"I'm fine." Liu Jinghui couldn't stand this, waved his hand and said: "It's all in the past. The grievances suffered in handling cases are nothing. As long as the case is solved, all efforts can be recovered many times..."

Jiang Yuan interrupted Liu Jinghui's words: "I mean, smoked beef can be made very delicious, which smoked chicken can't compare to no matter what. My father makes American Texas smoked beef at home, and the taste is very good. Use an American large oven, start making it in the afternoon of the first day, put firewood to smoke for a whole night, and start eating at noon the next day. The fibers of the beef are melted, and the fully cooked beef has a lot of meat juice..."

"Wang Chuanxing, bring the map over." Liu Jinghui shouted at people while turning his head.

Wang Chuanxing held a large map over. This was put in the trunk when going out.

Liu Jinghui pulled Jiang Yuan to find a restaurant with few people, put a few tables together, and started drawing on the spot.

"Let's make the first picture, with the transaction location as the center, and the radius as the boundary of six kilometers first, how about it? Actually, 3 kilometers is about the same." Liu Jinghui said while starting to draw.

For criminal police in the reasoning stream, basic skills such as geographical portrait must be mastered.

Corresponding statistical conclusions are undoubtedly the cornerstone of the reasoning stream.

It's like the crime pattern theory Liu Jinghui said, which is a basic understanding. Criminals actually tend to commit crimes in familiar areas, because crimes in unfamiliar locations not only increase the risk of exposure, but also waste the criminal's time and energy.

Yes, criminals also have time, energy, and money expenditures.

How far is this travel distance? According to statistics, the average distance of crime in most areas is within 3 kilometers. Specifically, the travel distance of violent attacks is generally short. The statistics of Sheffield, UK, is 2.4 kilometers, and Lexington, USA, is only 1.13 kilometers. In contrast, pickpockets in Sheffield will go 4 kilometers away to pickpocket, while pickpockets in Dallas, USA, are willing to go 9.66 kilometers away.

Similarly, the average travel distance of criminals in rape cases in Washington is 1.85 kilometers, and Dallas is 6.28 kilometers; the average travel distance of robbery in St. John, Canada, is only 0.69 kilometers, while robbers in Washington are willing to run 3.38 kilometers.

In terms of burglary, criminals in Ottawa, Canada, are only willing to walk 0.56 kilometers, Dallas, USA is 4.02 kilometers, and Sheffield and Harrow in London are 2.95 and 2.98 kilometers respectively.

In summary, Canadians are relatively home-loving and like to commit crimes within walking distance. British people are also very mediocre and rigid in terms of crime. Even criminals hold on to the world average and refuse to let go. Americans are the most unrestrained and are willing to go very far to commit crimes, only a little impatient when raping.

Liu Jinghui kept measuring the map with a ruler, and then started drawing lines with a compass.

Wang Chuanxing served on the side, watched for a while, and asked: "I thought you would draw a few 3-kilometer circles directly. Why is the size of each circle different?"

Liu Jinghui said while drawing: "Because travel distance is not straight-line distance. The 3-kilometer circle you said is equivalent to the shortest distance between two points on the map. This is Euclidean distance, and the accuracy is too low. I measured Manhattan distance, also called taxi distance, which is equivalent to you going from one place to another. You can't walk the shortest distance from the air, right? Walking on the ground, the shortest distance a car takes is called Manhattan distance..."

Wang Chuanxing was also admitted to the Criminal Police Detachment with a high score, and immediately recalled: "The hypotenuse of a right triangle is equivalent to Euclidean distance, and the sum of the two right-angle sides is equivalent to Manhattan distance."

"That's what it means. So do you know why Euclidean distance doesn't work now?"

"Because criminal suspects can't walk the shortest distance. At the very least, they have to walk Manhattan distance."

Liu Jinghui shook his head and said: "Because Euclidean distance is Euclidean-Distance, abbreviated as ED, ED doesn't work."

Wang Chuanxing shivered coldly.

Liu Jinghui's circles were soon drawn all over the map.

Li Si Ge and others have quite a lot of transactions, totaling dozens of times. And these transactions, whether it is Li Si Ge or Fat-Wrapped Muscle, have been recorded and timed.

It is impossible not to record. If you don't record the amount of goods and the remaining amount you get, there will be problems when talking about prices and shipping, etc., and it is easy to be fooled by subordinates.

Yuan Bomin and others finished their work and also came to the restaurant to watch.

The circles of circles made by geographical portrait are still relatively straightforward. Everyone can find that most of the circles intersect on three or four streets.

"Does the criminal live nearby?" Yuan Bomin was a little uncertain. This looked a bit too childish.

Liu Jinghui also shook his head and said: "The criminal is definitely familiar with this area. But not necessarily living nearby. Continuous criminal offenders generally have two modes. One mode is the mode of looting nearby, that is, living nearby. The other is the mode of going out to commit crimes, that is, specifically going to a place far from home to commit crimes. The theory in this regard..."

"No matter which mode, the criminal is likely to come and go here many times." Jiang Yuan interrupted Liu Jinghui's excitement and said: "Even if people and goods are separated, even if the big demolition doesn't have to deliver goods in person, but for the volume of this case, the big demolition himself or his confidant must plan the transaction location and transaction route every time, which requires stepping on the spot in advance and being familiar with the local area."

"This is certain. I think they have to come over to see in advance every time. Otherwise, the construction status of Wu Jiao Ge here may change after a period of time." Liu Jinghui agreed and further said: "Make a bold guess, I think the criminal or the criminal's confidant, the person responsible for transportation, must have a reasonable reason to come and go in this piece, work, study or life, at least have to raise a little white face here."

"This can be used as a direction for subsequent screening." Jiang Yuan agreed for the time being.

"And then?" Yuan Bomin asked impatiently.

Jiang Yuan stared at the map for a long time. At this time, he pointed to a street slightly to the east and said: "In this case, I think we can concentrate on collecting the monitoring of this street. Collect the monitoring three days before and after the transaction day."

"This street is the main commercial street." Yuan Bomin was a little numb when he saw the location, and hurriedly said: "There are community shopping malls, restaurants, snack bars, and street shops on this street. The flow of people is too large."

"It's not that difficult. It's still smaller than the range of a few kilometers around Wu Jiao Ge." Jiang Yuan smiled.

"Although it is said so..."

"The criminal will definitely have some different characteristics." Jiang Yuan comforted Yuan Bomin in reverse and said: "Think about it, people who trade several kilograms or even more than ten kilograms of drugs every time, even if he doesn't deliver goods in person, he will definitely have some characteristics on him."

"That's for sure." Yuan Bomin agreed first, then asked: "Where do you want to start? I mean, for example, what characteristics?"

"For example... rich?" Jiang Yuan smiled and said: "All the poor people on the whole street, those with a monthly income of less than 10,000, can be excluded first, and the working class can basically be excluded."

Yuan Bomin hesitated for two seconds and said: "I don't doubt it, I just want to say, can rich be seen?"

"The difference between migrant workers and drug dealer-level rich people can be seen by ordinary people." Jiang Yuan said while gesturing to Wang Chuanxing, and then pointed to Wei Shiyan who was wandering boredly by the wall, saying: "The living state of cattle and horses and pandas is naturally different."