Attending ex-girlfriend's wedding, arresting the groom's officer on the spot

Chapter 972 Lu Chuan's Suggestions

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 knew the people in the Criminal Investigation Team very well. None of them were good-for-nothings. They were all very experienced and he learned a lot from them when he was in the Criminal Investigation Team.

What's more, Qin Yong was personally in charge of the case, and Zhang Hui hadn't slept for several days, investigating the case.

Therefore, many of the obvious clues that Lu Chuan could think of must have been investigated by Zhang Hui, but so far a week has passed and there are still no pointing clues, which is a bit strange.

First, Lu Chuan examined the plaster. It was just ordinary plaster and there didn’t seem to be anything special about it.

However, the fact that a corpse can be placed inside a plaster statue shows that the mold used to make the plaster statue must be very large. It is impossible for ordinary people to make such a stone statue. In other words, the origin of the stone statue should be easier to trace in theory.

In addition, the statue could not have appeared in the Experimental Primary School for no reason. When was it delivered? Who sent it?
Lu Chuan believed that Zhang Hui had already conducted an investigation, but there were no clues so far, which meant that the investigation was not thorough.

"Has the composition of the gypsum been identified?"

Lu Chuan picked up a piece of plaster, wiped off the residue on it, and asked.

Liu Guodong nodded: "Yang Lin and his team did it the next day, but there is no special component in the gypsum. We have even traced the source of some of the materials in it, but there is nothing special. It is just an ordinary commercial gypsum that can be easily bought on the market."

Lu Chuan nodded. Since Yang Lin and the others had already done it, he naturally didn't need to do this repetitive work anymore.

There aren't many clues on the plaster.

"We have conducted a careful investigation inside and outside the entire plaster. We found some fingerprints on the outside, which we have collected and compared, but from the current situation, there are no directional clues and we cannot identify the suspect."

Seeing Lu Chuan carefully examining the plaster sculpture, Liu Guodong explained to him some of the work done by the on-site survey office before.

While listening carefully, Lu Chuan continued to inspect the inside of the plaster.

Liu Guodong and his team just said that the fingerprints on the outside are new, old, adults' and students', which means that this plaster has been touched by many people, not to mention that it has been in the Experimental Primary School for 5 years. Even if the murderer left any clues on it, it is estimated that they are 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.

Now it is being pieced together.

Lu Chuan wanted to find out if there were any clues left by the murderer inside the plaster. After all, the murderer might have left something of his own when making the plaster.

But unfortunately, because of the sealing of the corpse, some corpse oil seeped into the plaster, so the entire inner wall appeared gray-black and had a greasy feel.

Lu Chuan touched it and found it a little sticky.

Lu Chuan studied it carefully for about an hour, but did not find anything significant. From the technical perspective of on-site investigation, Lu Chuan's skills were definitely better than Liu Guodong and others, but these simple details were observed, and others could see what Lu Chuan could see.

After all, everyone has one nose and two eyes, so there is no reason why Liu Guodong and others cannot find what Lu Chuan can find. Moreover, Liu Guodong and his team have been studying the clothes on these statues and corpses for a week, and they have made very detailed observations and studies on every detail.

So naturally Lu Chuan didn't find any useful clues.

"On the surface, there is nothing of value. My suggestion is to finely crush the plaster and then perform trace evidence analysis."

Lu Chuan frowned and offered his 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 must be some residues left by the murderer in the plaster statue.

Lu Chuan nodded: "It must have been quite laborious for the murderer to make the plaster statue."

Lu Chuan gestured at the size of the plaster statue, which looked to be about 1 meters tall.

"The other party sealed the whole person in the plaster statue. First of all, the mold must be large enough, and the amount of plaster used must be relatively large. During the pouring process, the pouring of the plaster must not be interrupted, otherwise the statue will have cracks after it comes out."

Although Lu Chuan was not particularly familiar with the production process and craftsmanship of plaster statues, he was still clear about the main steps.

The production of such large plaster works is prone to failure.

Although the time it takes for gypsum to go from a molten state to a solidified state is not short, the solidification of gypsum is gradual, so the state of gypsum at each time stage is different.

Therefore, when making gypsum, the maker needs to make some adjustments to the ratio of gypsum water and gypsum powder injected at different times.

Simply put, the plaster injected first solidifies more slowly, and the plaster injected later gels faster. This way, during the plaster injection process, the plaster can be in a uniformly solidified state in the mold. In this way, the plasters can fit together tightly without any break marks.

Just thinking about it, you can tell that this requires a relatively high level of technical skill. When the murderer was making the plaster statue, it is impossible that no dandruff or hair from his body did not fall into the plaster.

But five years have passed, and it would certainly be very difficult to find it, so Lu Chuan’s suggestion is to crush the plaster and then conduct trace evidence analysis on the contents.

This is the limit of what can be achieved from the technical perspective of on-site investigation of gypsum.

Of course, the workload would be enormous. This plaster cast looks like it weighs hundreds of pounds. If it were all crushed for trace evidence analysis, Liu Guodong and others would probably not have time to rest for a month.

The key point is that the plaster sealed a corpse for 5 years, so after the plaster was crushed, there must be a lot of biological substances on it that belong to the deceased, which will definitely increase the difficulty of species analysis.

Taking this into consideration, Lao Bai meant to scrape off the plaster layer on the inner wall and start from the outside, and if that doesn't work, do the whole thing.

(End of this chapter)