National Forensic Doctor

The suspect left two scenes.

One is the house of the deceased after it was burned, and the other is the room rented by the murderer to observe the house of the deceased.

In a room after a fire, what can be inspected is bound to be limited. Jiang Yuan first chose the room rented by the murderer to inspect.

There is still something in this room. After all, although the murderer made some preparations, he was forced to leave after all. After all, he left something behind, including some traces of his life.

If we were to change to an ordinary criminal suspect, we could easily locate his identity with these things, and then it would be a typical pursuit, and there would be no need for an expert of Jiang Yuan's level to take action.

LV5's crime scene investigation is also explosive nationwide. Most of the exploration experts in the provinces can reach LV3, and a very few who can reach LV4 are considered top experts in the province. Across the country, experts who can reach LV5 are very rare. Most of the more than thirty provinces, cities and regions do not have such resources. That is, in places like Beijing, Shanghai, Guangzhou, Shenzhen and Hong Kong, there may be only a few, but not yet. Where are you working, whether you are traveling around the country, or even retired.

Although Qi Changye's department is very good, no matter how good the department is, its resources are limited, and so are its human resources.

In fact, because they are not responsible for detecting social cases, nor do they have a large number of scenes to investigate like the police, they cannot afford to have special experts in field investigation. Just borrow it when you need it most.

Experts at the LV5 level will not let their talents be wasted. It is difficult to keep them without using them. Just like Jiang Yuan in Ningtai County, if Huang Qiangmin does not actively sell them, Sooner or later, it will be the result of being borrowed and lost.

The murderer rented an apartment with a shopping mall on the four floors below and an old-fashioned tower with more than 20 floors above.

The location of the house is very good, because it is located in the center of the local business district, and daily needs can be reached on foot. However, the composition of the building is complex, from the shopping mall downstairs to the apartment upstairs. As long as you can find the location of the elevator and access control It’s almost pointless – there are so many people going in and out, just follow everyone else.

The separation method of 36 households with 6 staircases also makes the security in the building useless. Correspondingly, it is extremely difficult to obtain DNA and fingerprints from the corridors or elevators.

The room is a bit better, with an area of ​​nearly 100 square meters, two bedrooms and one living room. There was an astronomical telescope in the living room, with the mirror opening facing the balcony of the deceased's residence. In the other two bedrooms, one also has a window where the target can be seen, and the other is used as a tool room. There is a long table in it, with at least a dozen kinds of tools on it. The two iron shelves in the room On top, there are some scattered parts.

"The deceased Zhang Xuanting was used to opening the windows when he smoked, and he also had the same habit of smoking e-cigarettes. It is estimated that the murderer observed this characteristic and rented a house here." Qi Changye followed Jiang Yuan in and introduced the information he has so far. Condition.

"It's more reliable than using a sniper rifle in the movie." Jiang Yuan looked at the telescope with a bracket and felt a little bit more immersed.

"To be honest, using explosives is much more reliable than using a sniper rifle. Well, the murderer should have assembled explosives here. The explosives and the like were all taken away, but the remaining tools can still be used to determine." Qi Changye said He sighed and said: "So we must catch people quickly."

Jiang Yuan nodded silently. The murderer's target was obviously not Zhang Xuanting. It should be said that Zhang Xuanting was just a process leading to the goal. Silencing him was more likely to delay time in order to achieve the real goal.

Therefore, the murderer's main job in this room may be to assemble explosives, monitor or silence Zhang Xuanting, and most of them just do it casually.

To a certain extent, Zhang Xuanting is more like a fuse. When it burns out, the murderer knows that he should leave.

"So, the murderer assembled explosives in this room, and because of a certain opportunity, decided to kill Zhang Xuanting." Jiang Yuan walked to the window sill, looked at the dark night sky and bright lights outside, thought for a while, and said: "When the murderer determined that Zhang Xuanting was smoking an e-cigarette, he used a remote control device to kill Zhang Xuanting on the spot. Then, the murderer simply packed up and cleaned the room, then went downstairs to the opposite side and cleaned Zhang Xuanting again. Home, then set fire to it, leave?”

Jiang Yuan's speculation is that it is similar to the model of crime scene reconstruction, but the scope of the crime scene is expanded.

Qi Changye nodded slightly and said, "That's possible."

"After killing people, and then setting fire to Zhang Xuanting's house, wouldn't it be a bit unnecessary?" Jiang Yuan asked.

"It doesn't count. Zhang Xuanting is a habitual thief and is very careful when doing things. Although the house he lives in is rented, the door locks and other items have all been changed. The murderer also used violence to open the locks." Qi Changye was worried. Jiang Yuan didn't understand, and added: "When breaking into a house to kill, if the victim is prepared, it is still more dangerous. Life is his own, and no one really likes to take risks."

"It's like when predators hunt, they all pursue no harm?" Jiang Yuan somewhat understood.

"That's pretty much it. The area that the murderer can observe is only that large. It's hard to say whether the family has prepared anything else." Qi Changye paused and then said: "In addition, the murderer may also have the intention of confirming the death, and maybe even take it away. What is it..."

Jiang Yuan heard this and agreed: "The explosion power of the e-cigarette may not be enough, and it is possible that it did not kill him."

As he spoke, Jiang Yuan began to take pictures from beginning to end, and then checked bit by bit.

Naturally, the scene here has been fucked over before. Speaking of it, there are not many first scenes that Jiang Yuan has actually appeared in. Most experts actually have the same problem, because they travel around all year round and see everything. The local police checked a round of evidence, and it was naturally more difficult.

Some serial killers fell into the hands of such experts. After committing multiple crimes, they found that the police could not find them, so they committed another crime within a short period of time. As a result, they fell directly into the hands of experts who had not yet left. Backlogged cases were turned into cash, and then all were caught...

"After reading here, go downstairs." Jiang Yuan spent more than two hours scanning the house of less than 100 square meters.

Qi Changye had been impatient for a long time and did not dare to rush. Only then did he ask: "Have you found anything?"

"The problem now is that even if the identity of the murderer is determined, it is likely to be a false identity. As a result, conventional identification measures such as DNA and fingerprints are useless."

Qi Changye was stunned: "That's true. Then...do you have any idea?"

"We can only let the evidence speak for itself. Let's take a look." Jiang Yuan actually has some subtle means, such as the secret weapon that often pulls the trigger, forensic botany, which can search for the characteristics of a specific location. At this time, maybe he can Use it.

However, forensic botany also has its troubles. One is that it is time-consuming and laborious to do. If Jiang Yuan starts looking for pollen now, it may be several days before he finds the place, which is not in line with his current pursuit.

What Qi Changye expected now was for Jiang Yuan to directly report the room number and then rush in for a meal.

For Jiang Yuan, choosing which piece of pollen to use as a target was a problem.

If there is a corpse, I didn't mention it. Just look for the pollen on the corpse. Most of the locations found are meaningful. But in the murderer's house, which area or object should be chosen as the target? It's possible that after you've worked so hard, you'll find that you got a meaningless result.

Therefore, using forensic botany at this time is a high-risk, high-investment and high-return activity. Jiang Yuan does not want to choose it unless it is a last resort.

Several people then moved to Zhang Xuanting's residence which was set on fire.

Zhang Xuanting rented this place, and the decoration, furniture, etc. were all provided by the landlord. After a fire, the fire extinguished the fire. The objects in the house were either exposed to fire or water, and there was no intact part.

In this kind of fire scene, the evidence is basically destroyed, but the fire scene itself is another piece of evidence, including smoke marks, burning marks, spread marks, carbonization degree, etc., which can reflect the changes at the fire scene. General fire investigators also conduct four-step exploration based on this, that is, environmental exploration, preliminary exploration, detailed exploration, special exploration, etc.

Jiang Yuan continued to do this, and naturally obtained a series of evidence, but none of it played a decisive role.

"I'll go back and think about it. I have to check the surveillance again." Jiang Yuan was not in a hurry. In terms of skill level, he is now the best in the country. The murderer has left many clues. Now it just depends on which direction to cut in.

What's more, he still has some tricks he hasn't used yet.

No matter how anxious Qi Changye was, he had no choice but to follow Jiang Yuan.

After such a round of troubles, it was already working time when we returned to the police station.

Jiang Yuan was also very sleepy, but Qi Changye stood by and looked at him with golden retriever-like eyes. In addition to the special circumstances of the case, Jiang Yuan could only cheer up, order a cup of coffee, drink it, and watch the video.

As the murderer entered and exited the apartment every day, he was inevitably photographed from the front and back. However, the murderer always wore a mask and sunglasses, so the facial information collected was slightly insufficient.

Jiang Yuan took a few pictures and did some rough image enhancement, but the effect was average.

He kept watching like this. Qi Changye was so drowsy that he almost fell asleep when Jiang Yuan slapped him awake.

"Look at the murderer's shoe cabinet..." Jiang Yuan's eyes were a little red, but his eyes were still bright.

"Shoe cabinet..." Qi Changye frowned and looked at the photos shown to Jiang Yuan. He knew that he would not make a mistake, so he thought about it carefully and said, "Is it the type of shoes? Outdoor shoes, hiking shoes, and formal leather shoes..."

"What you want to look at is what is not there." Jiang Yuan pointed to a few empty spaces on the shoe cabinet, took out a few photos, and said, "Look at the pairs of shoes he was wearing at this time, none of them appear in the shoe cabinet. inside."

"Did the murderer take him with him?" Qi Changye suddenly thought of the reason and frowned: "He still had time to prepare his luggage, although it is a bit strange to bring a few extra pairs of shoes..."

"All he took away were Zegna shoes." Jiang Yuan interrupted Qi Changye, then took out a stack of printed photos and said to him, "These are the shoe samples I checked on the official website, and they were confirmed by comparison on site. The murderer took away at least four or five models of shoes of this brand. It seems that he is a loyal fan of Ermenegildo Zegna shoes."

Qi Changye nodded slowly: "Some people are used to wearing a certain type of shoes and will keep buying them again..."

At this point, Qi Changye finally reacted: "Do you think he will buy shoes from this brand again?"

"Just go back to the past first." Jiang Yuan felt that Qi Changye was still a little sleepy, and then said: "Even if there are many rich people in the capital, and they buy multiple pairs of shoes of the same brand in succession, and they are in shoe size 43, we will If you know the color and appearance of four of the shoes, you can always find out some information about the customer."

Jiang Yuan clicked on the shoe sample in the photo with his hand and said emphatically: "As far as I know, luxury brands pay special attention to the long-term behavior of customers. If this person buys shoes as a new customer every time, I guess you can only buy relatively basic styles. If you want popular or limited editions, his membership will have to be retained for a long time... It depends on whether you can get the brand to cooperate."

Qi Changye smiled and did not answer Jiang Yuan's question at all. He only nodded seriously: "I won't let him escape this time."