Inferring the condition of a corpse through a certain bone is basically based on statistics.
For example, it is easy to judge height based on the long bones. That is, the thigh bones, calf bones, and humerus of the upper limbs, etc. - it is easier to understand with the description on the pork stall, which is the tube bone.
The common saying among the people, "This child has long calves, he will be tall when he grows up" is essentially similar to the judgment model of forensic doctors.
However, if we really want to talk about accuracy, there are problems.
If height is the target, there will definitely be a difference between a model with long legs and a model with short legs, judging by the long bones.
For this reason, forensic doctors began to make various regression equations based on bones at different locations to determine height.
The same goes for the lumbar spine.
It's just a little more complicated.
For example, we must first distinguish between men and women.
Secondly, the first lumbar vertebra to the fifth lumbar vertebra are different.
Each lumbar vertebra has ten measurement points, including the anterior height of the vertebral body, the posterior height of the vertebral body, the superior sagittal diameter of the vertebral body, the inferior sagittal diameter of the vertebral body...
There are a total of 19 types of regression equations formed in the end.
It's annoying to memorize it.
Normal people are unlikely to recite this kind of regression equation. They just know where to look it up.
But Jiang Yuan took the LV3 Forensic Anthropology script, so he couldn’t look it up. Memorizing it directly would be better.
For laymen, this will most likely not be of much concern.
It's different for people in the industry.
It's like ordinary people buy a reference book such as "Anthropometric Manual", or they can specially choose one published by Cihai Publishing House. As a result, Jiang Yuan seemed to have memorized the "Anthropometric Manual".
In any workplace, who would not be confused when encountering such a colleague?
Jiang Yuan didn't have anything to say. He just measured a few more data with a ruler and silently checked the calculations several times. He felt that there was not much difference.
Things like regression equations can originally be understood as formulas for summarizing experience. The formula is there and the data is here. When you put it in, you will get whatever result you get.
A young doctor secretly washed his gloves, took off his gloves, washed his hands again, put on new gloves, then searched his cell phone, and came to the same conclusion.
Then, he quietly cooked the bones.
Wang Lan pondered and said: "There shouldn't be many such people in Qinghe City, a 40-year-old woman who is 1.7 meters tall."
"I'm afraid he's not from Qinghe City. He was thrown far away and buried nearby." Another city bureau forensic doctor muttered slightly.
Fortunately, it was Wang Lan who took the lead this time. He really had no confidence at all in the case in front of him.
If a murderer kills one person, he may be full of flaws. If he kills four people, he should have gained some experience.
Some of the forensic doctors here have never participated in four dismemberment cases.
And the handling of these four corpses was really good. If the water in the reservoir hadn't dropped to a historically low level, no one would have known there were corpses here for decades.
Wang Lan frowned and said: "It is indeed a general rule to dump them far away and bury them close, but these corpses are closer to being buried than simply throwing them away. Moreover, four times in a row, in the same place, they are not buried.
It’s like it’s too far away.”
Throwing things far away and burying them close is a rule summarized by criminal investigators.
Generally speaking, when the murderer dumps the body, if the distance is far away, he will choose to dump the body directly, and if the distance is close, he will choose to bury the body.
This is very interesting psychology.
In fact, if the body is dumped and buried far away, it will naturally be more difficult. But in actual operation, the murderer is in a strange place and is obviously not willing to stay too long. In other words, the murderer is willing to use it to dispose of the body.
The time actually has a range...
What the two discussed was actually this issue.
Are the corpses in the reservoir considered dumped or buried?
The core point of burying corpses is that it actually takes time to excavate. Because the murderer feels very insecure in a strange place, so the murderer usually does not want to be in a place far away from his familiar place and far away from the center of his life and work.
Too willing to spend too much time and energy digging.
But it is impossible to say that the murderer did not want to dump the body in a more secretive manner.
Therefore, sinking into a reservoir tends to throw the body away.
If so, it means that the source range of the corpse has been greatly expanded. The victim may not necessarily be from Qinghe City, or even die in a nearby city.
Just from the perspective of determining the source of the corpse, this level of difficulty is almost overwhelming.
Wang Lan shook his head slowly and continued: "My personal preference is to dump the body. I'll leave the specific investigation direction to the leaders."
Jiang Yuan listened silently.
He also prefers that the source of the corpse is nearby. However, this is not an exclusive answer, and unexpected situations may still occur.
However, even if Jiang Yuan is the person in charge, he will come to the same conclusion as Wang Lan. Otherwise, this case will be too difficult to handle from a forensic perspective.
Through the technology of forensic anthropology, searching for the source of corpses is essentially looking for intersections. It is like drawing circles on a blackboard and constantly looking for the intersection points of these circles. In the end, when the number of people intersecting is small enough, it will be easier to
The source of the body was found.
For example, the corpse numbered 1 in front of me is a circle for women, another circle for those who are about 40 years old, another circle for those who have given birth, and another circle for those who are 1.7 meters tall.
If you add a circle that meets these conditions to a circle of missing people in Qinghe City, the final intersection will probably be only one, or at most a few people who meet it.
Then we can basically determine the source of the corpse.
Determining the source of the corpse is the first step in this type of case. It can even be said that only by determining the source of the corpse can the case have a foundation - this is also Wang Lan's task.
"Um... Xiaozhuang, please make a record." Wang Lan clicked on the name of a young forensic doctor.
Xiaozhuang said "Oh" and immediately took off his gloves and washed his hands.
After a lot of fussing and recording, another pot of corpses was cooked.
Skim off the foam, pour out the corpse soup, fish out the bones with fascia, shovel them clean, and unfold the characteristic bones on the second dissecting table - the reason why we need to skim off the foam is also the experience of the previous pot.
, just pour the soup, the foam will stick to the bones, and you will have to clean it twice.
As a result, the dissecting table is a bit inadequate.
Four corpses is still too many. The autopsy room in Qinghe City has already increased its demand, but it cannot allow one corpse to occupy two tables.
However, it is not possible to put the body bag with the plastic bag directly on the ground. Sewage flows across the ground, and the plastic bag is actually part of the evidence...
So, after a lot of fuss, he carried the other two unopened packages of corpses to an autopsy table, and then concentrated on disposing of the two opened packages of corpses.
There is only one person in a body bag, and there are still stones and possibly water seeping into it. To lift it up high, it will take three or even four people to work hard.
As a female forensic doctor, Wang Lan can only stand aside and cheer...
after an hour.
The forensic doctors who went to have dinner came back. At this time, the second corpse here was also sorted out.
"35 years old, male, about 1.7 meters tall..." Jiang Yuan quickly made a judgment.
Wang Lan agreed and muttered to himself: "There are men and women, but they are the same height."
"Serial killers like to kill people who are 170 centimeters tall, regardless of gender or age." A forensic doctor made a personal summary.
Xiaozhuang, who was taking notes next to him, couldn't help but raise his head and said, "Do you want to listen to what you are saying?"
"What?"
"In China, if you like to kill people who are 170 centimeters tall, they will be exhausted."
"Oh, there may be other superimposed factors..."
Xiaozhuang was too lazy to tell him, and instead said: "I think this method of dumping the body is a bit like the double-faced forensic doctor in the American TV series. It is also called the bloodthirsty forensic doctor."
"I've only read the beginning, how did he throw it away?" Wang Lan immediately paid attention to it. Copycats are a big category among murderers.
Xiaozhuang sorted out his words and said: "He is often in a container, covered with plastic, wrapped himself up, wearing protective clothing and the like, and a mask. Then he strips the person naked and ties him to the table.
Killed with one knife, then cut the body into pieces, put it into plastic bags, and finally transported it to the sea and dumped the body."
Wang Lan pondered for a while and said: "Then he needs to buy a lot of plastic sheets, a separate house or space, and protective clothing and masks. In addition, our murderer is definitely not a forensic scientist. He used a chainsaw to dismember the body.
, the plastic sheet is easily punctured..."
"We need transportation. In addition, the body bag is too heavy, and one person may not be able to move it," Jiang Yuandao said.
"So, is it possible that multiple people committed the crime?" Wang Lan's eyes lit up.
Jiang Yuan did not respond to his words, but fell into deep thought.
After a moment, Jiang Yuan said slowly: "I think, even if multiple people committed the crime, the bodies have been dismembered like this, why do they still need to be packed in such a big body bag?"
Wang Lan raised his head in horror.
Jiang Yuan continued: "If he knew how to sum up his experience, it would be much lighter and easier if he divided the body into two or even four bags. It is the stone that sinks to the bottom, not the weight of the body itself."
Not only Wang Lan, but everyone present swallowed their saliva.
"There are only these four body bags at the scene, so if the crime escalates..." Xiaozhuang took a deep breath.
Jiang Yuan nodded and said: "If the crime escalates, the murderer is likely to choose deeper waters and smaller body bags."
"It makes sense." Wang Lan sighed heavily and said to Xiaozhuang: "Call the detachment leader and ask them to find the frogmen and go into the water to look for it."
