Chapter 972 Lu Chuan’s Suggestion
Lu Chuan quickly got into working mode.
Since the origin of the statue is unclear, it is impossible to find out who made the statue.
Lu Chuan, the people in the Criminal Investigation Detachment, knew very well that no one was a loser. These people were very experienced and he learned a lot from everyone when he was in the Criminal Investigation Detachment.
What's more, Qin Yong is personally responsible for the case. Zhang Hui has not slept for several days and has been investigating the case.
So there are many obvious clues that Lu Chuan can think of and Zhang Hui must have investigated them, but so far a week has passed and there are no pointing clues, which is a bit strange.
First of all, Lu Chuan checked the gypsum. It was just ordinary gypsum, and there seemed to be nothing special about it.
But the plaster statue can fit a corpse inside, which means that the mold for making the plaster statue must be very large. Generally speaking, it is impossible for ordinary people to make such stone statues. In other words, the origin of stone statues is theoretically It should be easier to check.
In addition, the statue cannot appear in the experimental primary school for no reason. When was it sent? Who sent it?
Lu Chuan believes that Zhang Hui has already conducted an investigation, but there are no clues so far, which means that the investigation is not clear.
"Have the composition of the gypsum been identified?"
Lu Chuan stuck a piece of gypsum on, wiped the residue on it, and asked.
Liu Guodong nodded: "Yang Lin and the others did it the next day, but there are no special ingredients in the gypsum. We have even traced the origins of some of the materials in it, but there is nothing special. I found that ordinary commercial plaster is readily available on the market."
Lu Chuan nodded. Since Yang Lin and the others had already done it, he naturally didn't have to do these repetitive tasks.
There are not too many clues in the plaster.
"We have carefully investigated both the inside and outside of the plaster, and some fingerprints were found on the outside. We have collected them and compared them, but judging from the current situation, there are no directional clues and we cannot identify the suspect."
Seeing Lu Chuan carefully inspecting the plaster sculpture, Liu Guodong explained to him and talked about some of the work done in front of the current survey office.
While listening carefully, Lu Chuan continued to inspect the inside of the plaster.
Liu Guodong and the others just said that the external fingerprints include new ones, old ones, adults, and students, which means that this plaster body has been touched by many people, not to mention that in the experimental primary school It’s been 5 years. Even if the murderer left any clues on it, they are probably gone.
So Lu Chuan's attention was not on the outside of the plaster, but on the inside of the plaster. In order to clean out the corpse, the plaster had been broken into pieces.
Now it's put together piece by piece.
Lu Chuan wanted to find out if the murderer might have left some clues inside the plaster, after all, the other party. It may be left behind when making plaster. Something of its own.
But unfortunately, some corpse oil seeped into the inside of the plaster due to the sealing of the corpse, so the entire inner wall was gray-black and had a greasy feel.
Lu Chuan touched it and found it was a little sticky.
Lu Chuanzai studied it carefully for about an hour, but he didn't make any big discoveries. From the technical point of view of on-site investigation, Lu Chuan's technology is definitely superior to Liu Guodong and others, but these simple detailed observations, what Lu Chuan can see can also be seen by others.
After all, everyone has one nose and two eyes. There is no reason why Liu Guodong and others cannot discover things that Lu Chuan can discover, not to mention the four of Liu Guodong studying these statues and corpses. It's been a week since I put on the clothes, so to speak. Every detail has been carefully observed and studied.
So of course Lu Chuan didn't find any useful clues.
"On the surface, there is nothing valuable. My suggestion is to crush the plaster carefully and then conduct trace evidence analysis."
Lu Chuan frowned and proposed his own suggestion.
"Oh? You mean..." Liu Guodong knew what was going on as soon as he heard Lu Chuan's suggestion. Lu Chuan must have suspected that there should be some remnants left by the murderer in the plaster statue.
Lu Chuan nodded: "When the murderer made the plaster statue, it must have been more laborious."
Lu Chuan gestured at the size of the plaster statue, and it looked like it was about 1.7 meters.
“The other party sealed the whole person in the plaster statue. First, the mold must be large enough. In addition, the amount of plaster used must also be relatively large. During this pouring process, the pouring of plaster must be certain. It cannot be interrupted, otherwise the statue will have broken marks after it comes out.”
Although Lu Chuan didn’t know much about the process and technology of making plaster statues, he still knew the main steps.
The production of such large-scale plaster is very prone to failure.
Although the time from the molten state to the solidified state of gypsum is not short, because the solidification of gypsum is gradual, the state of the gypsum is different at each time-like progress.
So when making gypsum, the producer needs to make some adjustments to the ratio of gypsum water and gypsum powder injected at different times.
To put it simply, the gypsum injected first should set slower, and the gypsum gel should be faster, so that the gypsum can be in a uniform solidification state in the mold during the process of injecting gypsum. , in this way, the plaster can fit together tightly without breakage.
Just think about it and you will know that this requires relatively high technology. When the murderer made the plaster statue, it was impossible for the skin flakes or hair on his body not to fall into the plaster.
But five years later, it would definitely be very difficult to find it, so Lu Chuan's suggestion was to crush the plaster and then conduct trace evidence analysis on the contents.
This is the ultimate that can be achieved from the technical point of view of on-site investigation on gypsum.
Of course, if this is the case, the workload must be very huge. This plaster seems to weigh hundreds of kilograms. If they are all crushed for trace evidence analysis, Liu Guodong and others will not need to rest for a month. .
The key is that the plaster also sealed a corpse for 5 years, so after the plaster was crushed, there must be a lot of biological material on it that belonged to the deceased. In this case, it would be difficult to analyze the species. It’s getting bigger again.
Considering this, Lao Bai means to scrape off the gypsum layer on the inner wall and start from the outside. If it doesn't work, then do it all.
(End of this chapter)