novelnext Chapter 1158 They are different
Chapter 1158 They are different
Chapter 1158 They Are Different
"Geographical profiling? Criminal geography and environmental criminology? I'm not sleepy anymore when you talk about this." Liu Jinghui suddenly became excited: "I am also quite interested in the Chicago School's crime analysis. By the way, if you talk about using theory for relevant practice, I have actually handled similar cases."
Jiang Yuan talked as he walked: "Oh, have you ever worked on a similar case?"
"Of course. Before you came along, I could only circle around and investigate cases without any clues. At that time, I made my judgments based on the crime pattern theory..."
"Is it useful?" Jiang Yuan didn't really want to discuss such a purely theoretical topic, but he was indeed a little curious.
"It is useful. For example, the crime pattern theory holds that the spatial and temporal interaction of crime elements makes it most likely that the crime will occur in an area where the activity spaces of potential criminals and potential victims overlap. I used this method to catch a serial rapist. I marked all the activity areas of the victims, and then looked at the suspect to see if he had any activity areas that intersected with these victims..."
Jiang Yuan interrupted Liu Jinghui's endless chatter: "Is it easy to do?"
Liu Jinghui was stunned for a moment, then he began to recall. After a while, he said, "After determining the scope, we conducted investigations and visits, and finally caught the criminal... It must have been difficult to do. I did investigations before, but I didn't have the support you have."
Criminal geography and environmental criminology, etc., are theoretical studies on crime based on geographical factors. Further developments include crime pattern theory, daily activities theory, rational choice theory, criminal space theory, etc.
These theories are actually useless when facing some small cases. Because small cases can be left unsolved. If you really can't find any clues, just give up.
Most police officers will only use these unintuitive theories as a last resort when they are faced with a major case that must be solved.
Foreign aid like Liu Jinghui, even if he goes to fight under the name of a superior unit and uses these crime theories to solve cases, will still be regarded as a scholar. The cooperation of various units is somewhat slack. If the task is too heavy, some people will say strange things to your face. It is common for things to go wrong.
Jiang Yuan nodded, not quite understanding.
Liu Jinghui looked at the confused look of his dragon and couldn't help but sigh: "People can't imagine what they haven't seen!"
"Geography does restrict people a lot. People are prisoners of geography." Jiang Yuan nodded in agreement. Northerners who have never seen the sea find it hard to imagine the rough seas on a typhoon day. Southerners who have never seen snow find it hard to imagine the coldness of water turning into ice.
Liu Jinghui shook his head and said, "I'm talking about handling cases. When we're out there working on cases, sometimes we run into things that you probably wouldn't even imagine... Just like, for someone like you who has a ranch at home, you can't imagine that some people would do something strange just to eat a smoked chicken."
Jiang Yuan looked at Liu Jinghui with sympathy and curiosity.
"I'm fine." Liu Jinghui couldn't stand this, waved his hands, and said: "It's all in the past. Whatever grievances I suffered while handling the case are nothing. As long as the case is solved, all the efforts can be recovered many times over..."
Jiang Yuan interrupted Liu Jinghui and said, "What I mean is that smoked beef can be made very delicious, which is incomparable to smoked chicken. The American Texas smoked beef that my father makes at home tastes very good. He uses a large American oven, starts making it in the afternoon of the previous day, smokes it with firewood all night, and eats it at noon the next day. The fibers of the beef are melted, and the well-done beef has a lot of gravy..."
"Wang Chuanxing, bring the map here." Liu Jinghui turned around and called for help.
Wang Chuanxing came over excitedly with a large map in his hand. He had put it in the trunk when he went out.
Liu Jinghui took Jiang Yuan to find a deserted restaurant, put a few tables together, and started drawing on the spot.
"Let's make the first map first. With the transaction location as the center and a radius of six kilometers, how about it? In fact, three kilometers is about right." Liu Jinghui said as he began to draw the map.
For detectives who specialize in reasoning, crime theories such as geographic profiling are basic skills that must be mastered.
The corresponding statistical conclusions are undoubtedly the cornerstone of the flow of reasoning.
Just like what Liu Jinghui said about the crime radius, it refers to the distance that the criminal travels. A simple understanding is that criminals actually tend to commit crimes in familiar areas, because crimes in unfamiliar places not only increase the risk of exposure, but also waste the criminals' time and energy.
Yes, criminals also have time, energy and money to spend.
How far is this travel distance? According to statistics, the average crime distance in most areas is within 3 kilometers. Specifically, the travel distance for violent attacks is generally shorter. The statistics in Sheffield, UK are 2.4 kilometers, and Lexington, USA are only 1.13 kilometers. In contrast, pickpockets in Sheffield will go 4 kilometers away to steal, and pickpockets in Dallas, USA will go 9.66 kilometers away.
Similarly, the average travel distance for rapists in Washington is 1.85 kilometers, while in Dallas it is 6.28 kilometers; the average travel distance for robberies in St. John's, Canada is only 0.69 kilometers, while robbers in Washington are willing to run 3.38 kilometers.
When it comes to burglary, criminals in Ottawa, Canada are only willing to travel 0.56 kilometers, while in Dallas, USA it is 4.02 kilometers, and in Sheffield and Harrow in London it is 2.95 and 2.98 kilometers respectively.
In summary, Canadians are more home-loving and prefer to commit crimes within walking distance. The British are also moderate and rigid in terms of crime, even criminals stick to the world average and refuse to let go. Americans are the most uninhibited and are willing to commit crimes far away, except when it comes to rape.
Liu Jinghui kept measuring the map with a ruler, and then started drawing lines with a compass.
Wang Chuanxing was waiting nearby. After watching for a while, he asked, "I thought you could just draw a few 3-kilometer circles. Why are the sizes of the circles different?"
Liu Jinghui said as he drew: "Because the travel distance is not a straight-line distance. The 3-kilometer circle you mentioned is equivalent to the shortest distance between two points on the map. This is the Euclidean distance, which is too inaccurate. I measured the Manhattan distance, also called the taxi distance, which is equivalent to when you go from one place to another. You can't walk the shortest distance in the air, right? You have to walk on the ground. The shortest distance a car travels is called the Manhattan distance..."
Wang Chuanxing, who also got into the Criminal Police Brigade with high scores, immediately recalled: "The hypotenuse of a right triangle is equivalent to the Euclidean distance, and the sum of the two right-angled sides is equivalent to the Manhattan distance."
"That's what I mean. So now you know why the Euclidean distance doesn't work?"
"Because the suspects can't possibly walk the shortest distance. At the very least, they have to walk the Manhattan distance."
Liu Jinghui shook his head and said, "Because Euclidean distance is Euclidean-Distance, abbreviated as ED, ED is not acceptable."
Wang Chuanxing shivered from the cold.
Liu Jinghui's circle soon filled the map.
The number of transactions between Brother Li Si and others was quite large, totaling dozens of times, and for these transactions, both Brother Li Si and Fat Bag Muscle kept accounts and recorded the time.
It is not possible not to keep records. If you don't keep records, you won't even be able to figure out the quantity of goods received and the balance. There will be problems when discussing prices, delivery, etc., and it will be easy for you to be fooled by your subordinates.
After Yuan Bomin and others finished their work, they also came to the restaurant to watch.
The geographical portrait is a bunch of circles within circles, which is relatively straightforward. Everyone can see at a glance that most of the circles intersect on three or four streets.
"Does the criminal live nearby?" Yuan Bomin was a little unsure. This seemed a bit too trifling.
Liu Jinghui also shook his head and said, "The criminal must be familiar with this area. But he doesn't necessarily live here. There are generally two patterns for serial criminals. One pattern is the nearby plundering pattern, that is, living nearby, and the other is the out-of-town crime pattern, that is, deliberately committing crimes far away from home. The theory in this regard..."
"No matter what kind of person it is, the criminal is likely to have come here many times." Jiang Yuan interrupted Liu Jinghui's excitement and said, "Even if the people and goods are separated, even if the big demolition family does not need to deliver the goods personally, but considering the size of this case, the big demolition family himself or his confidants must at least plan the transaction location and route for each transaction, which requires scouting the place in advance and being familiar with the local area."
"That's for sure. I think they have to come here in advance every time. Otherwise, the construction status of the Pentagon Pavilion may change after a period of time." Liu Jinghui agreed, and further said: "To make a bold guess, I think the prisoners or their confidants, the people in charge of transportation, must have a reasonable reason to come and go in this area, whether for work, study or life, and at least have to keep a gigolo here."
"This can be used as a direction for subsequent screening." Jiang Yuan agreed tentatively.
"And then?" Yuan Bomin couldn't help asking.
Jiang Yuan stared at the map for a long time, and pointed to a street a little to the east. He said, "In this case, I think we can focus on collecting surveillance footage on this street. Let's take a look at the surveillance footage from three days before and after the trading day."
"This street is the main commercial street." Yuan Bomin was a little confused when he saw the location, and said hurriedly: "There are community shopping malls, restaurants, snack bars, and small shops on this street. The flow of people is too large."
"It's not that difficult. It's much smaller than the several kilometers around the Pentagon." Jiang Yuan smiled.
"Even so..."
"The criminal must have some unique characteristics." Jiang Yuan tried to comfort Yuan Bomin and said, "Think about it, a person who trades several kilograms or even dozens of kilograms of drugs every time, even if he doesn't deliver the drugs himself, he must have some characteristics."
"Of course." Yuan Bomin agreed, then asked, "Where do you want to start? I mean, what are the characteristics?"
"For example... rich?" Jiang Yuan smiled and said, "The poor people on the whole street, those who earn less than 10,000 yuan a month, can be ruled out first. The working class can basically be ruled out too."
Yuan Bomin hesitated for two seconds and said, "I'm not doubting it. I just want to ask, can Fu see it?"
"Ordinary people can tell the difference between a worker and a drug dealer." Jiang Yuan said to Wang Chuanxing, then pointed at the guard who was strolling by the wall out of boredom, and said, "The living conditions of cows, horses and pandas are naturally different."