Chapter 653: Investigation Direction

When Jiang Yuan proposed splitting the cases, Tao Lu was already won over.

For cases suspected of being serial homicides, the detachment and even the branch bureau would spare no cost in their investigation. A screening of over a thousand people, a rare occurrence in Shannan Province, was simply nothing to the Zhengguang Branch Bureau.

It didn't even need to reach the level of a cold case; for ordinary homicides, or even any of the eight major serious crimes, organizing a screening at the thousand-person level was quite common. To make Tao Lu or the bureau chief hesitate, the scale would have to reach at least three thousand people.

How much funding does it take to organize a screening of three thousand people? People who have been married can imagine how much it costs to organize a wedding banquet for three thousand people without accepting gift money; it would at least be that figure.

Continuous days of screening are equivalent to continuous days of hosting a wedding...

Therefore, after such a meticulous screening, every single clue is precious.

That Jiang Yuan could find clues just by relying on the case files was enough of a feat for Tao Lu to make a decision, not to mention his glorious track record.

The "Rainy Day Corpse Case" special task force was quickly assembled. There were no tricks; it was still led by the two major brigades of Liu Cheng and Cui Qishan. Tao Lu also considered that Jiang Yuan had a deeper familiarity with Liu Cheng, and the criminal police of both brigades were already somewhat familiar with Jiang Yuan.

Criminal investigation is still an industry that values relationships very much. With a bit of trust, things are definitely much more convenient to do.

The next day.

Tao Lu presided over a case analysis meeting. In front of the criminal police, he said: "In the previous case, the two killers were captured one after another, and the case as a whole proceeded very smoothly. This was an extremely complex homicide case involving multiple victims, including overseas Chinese, involving acts such as corpse disposal and burial, and possessing the nature of serial homicide. The investigation process of this case was outstanding, and the bureau chief has already requested commendations for everyone... However..."

Tao Lu said: "In the final stage of this case, some unexpected situations occurred. This... was mainly my decision-making error; everyone need not worry."

Without waiting for the crowd to react, Tao Lu continued: "The celebration banquet can only be postponed. On one hand, it is the determination of responsibility; on the other hand, the two killers are involved in many cases, and there is a lot of evidence that needs to be secured. We have to wait a little bit here... However, the case waits for no one!"

Tao Lu looked at the crowd and said: "This time, Team Leader Jiang Yuan has chosen a highly challenging case: the Rainy Day Corpse Case. If we can solve this case, it will be an excellent comfort to the victims and their families, and for our detachment, it is also a good opportunity to prove our combat effectiveness... Well, I will hand the time over to Jiang Yuan..."

Jiang Yuan stood up upon hearing this, smiled at the crowd, took the remote control for the projector, clicked a few times, and then said: "The Rainy Day Corpse Case is a rather strange case..."

Liu Cheng and the others all sat up straight to listen. It wasn't because Jiang Yuan's description of the case was strange, but because Jiang Yuan himself had enough appeal.

"The Rainy Day Corpse Case involves a total of four cases. The evidence obtained is relatively scarce. The killer knows how to clean up the scene and has a certain level of professional ability..." The professional ability Jiang Yuan spoke of had to be at least at the LV2 level of scene cleanup.

This had already gone beyond the scope of scene cleanup like mopping the floor or pouring some detergent. The meticulousness of the cleanup, the order of the cleanup, the items cleaned, etc., were all very important. Otherwise, redundant actions would only leave more clues for the police.

Jiang Yuan did not continue to talk about the previous investigation direction and continued: "The identities of the four corpses are clear, and there is a lack of intersection in terms of interpersonal relationships. However, in the process of reading the case files, I discovered that the third corpse, which is the third case, has obvious differences from the other three cases."

Jiang Yuan clicked the remote control at will and displayed a few photos. Some were the bloated, unrecognizable corpses from the first case, and others were corpses discovered earlier but also changed in appearance.

Jiang Yuan detailed the analysis he gave to Tao Lu and continued: "Some abnormal situations of the third corpse are unreasonable. Especially with the existence of the fourth corpse, the killer changed the murder weapon, changed the stabbing position, and the force used also changed. These are all abnormal. As far as the current situation is concerned, I am inclined to believe that the third corpse is a copycat crime."

"The details of the Rainy Day Corpse Case were not released. How was it copied?" Liu Cheng couldn't help but ask when he heard this.

Jiang Yuan nodded and said: "But it was not strictly kept secret. Moreover, this case sounds complex, but it is actually highly operable: killing on a rainy day, using a dagger, then wrapping the corpse tightly before abandoning it, while strictly cleaning up the scene..."

"It sounds simple but is difficult to do." Liu Cheng said slowly: "One must have experience in killing, experience in cleaning up the scene, and must be good at using a dagger..."

The more he spoke, the worse his expression became. If considered from this direction, there was a high possibility that it was a law enforcement officer committing the crime. And such things had happened before; for example, various scandals were exposed from time to time in the US.

Jiang Yuan ignored this and only said: "My suggestion is to re-divide the case into two parts. One part is the third case, considering the situation of a copycat crime separately. The second part is the three cases of one, two, and four, reconsidering the connections between them. Currently, concentrate our strength and prioritize the third case."

"If the third case is a copycat crime, even if it is solved, the Rainy Day Corpse Case cannot be considered solved." Someone reminded in a low voice.

"The copycat of the third case, their understanding of the case as a whole, may perhaps serve as a breakthrough for the Rainy Day Corpse Case." Jiang Yuan paused and added: "Of course, a direct breakthrough of the Rainy Day Corpse Case is also possible, it's just a matter of priority."

Jiang Yuan's criminal investigation thinking has always been simple and direct. If there is any characteristic, it is based on his latest discoveries.

But it must be said that such criminal investigation thinking is hard to find fault with, and Liu Cheng and others naturally had no objections.

Tao Lu asked: "Jiang Yuan, will you arrange the work?"

"You should do it. I plan to stay in the lab today." Jiang Yuan explained: "In the case of moved corpses where the first scene has not yet been determined, forensic botany is still very useful."

For this kind of absolute difficulty-level case that also happened in the capital, Jiang Yuan had not considered conventional plans from the beginning.

Skills like crime scene investigation, footprint analysis, etc., were not rare in the capital. Experts at the LV3 or LV4 level, while not common, were easy to find when the task force needed them.

In other words, to solve a cold case that previous experts failed to solve with these skills, LV5 is the baseline, and it might not necessarily be very useful—the technicians of the task force at the time might only have had LV3 level, but they studied it for weeks or even months, and perhaps invited higher-level experts to study it together. Even if Jiang Yuan switched to LV5, without settling down to study for a period of time, he might not necessarily achieve results.

However, forensic botany is different. This kind of niche skill, let alone the capital, there are not many people who understand it nationwide, and those who can reach the LV2 level are as rare as phoenix feathers and unicorn horns.

Most importantly, the expert group of the Rainy Day Corpse Case had not tried to use forensic botany before, which gave Jiang Yuan a lot of room to play.

Tao Lu and the others naturally thought of the first case Jiang Yuan did when he rushed over, and they nodded repeatedly, hoping that Jiang Yuan could replicate his brilliance.

Liu Cheng and the others automatically and consciously arranged their subordinates. With the series of cases restarted, there was a lot to do. Furthermore, some criminal police also needed to hand over the cases at hand clearly.

Jiang Yuan went to the lab to pick pollen.

Time, place, and person—these three elements still play an important role in criminal cases. And in the "Rainy Day Corpse Case," the time could basically be determined, and the identities of the victims had also been confirmed after multi-party verification. The only thing that hadn't been found was the first scene.

But this time, Jiang Yuan was not very sure whether forensic botany would be effective.

Compared to the urban environment, forensic botany is actually more suitable for rural or wild states. ===== CHAPTER 654 =====