National Forensic Doctor
Chapter 762 - 705: From Nothing to Something

Chapter 762: Chapter 705: From Nothing to Something

The suspect left behind two crime scenes.

One was the residence of the burned victim, and the other was the room rented by the murderer to observe the victim’s residence.

The room that had burned was inevitably limited in what could be investigated, so Jiang Yuan chose to inspect the room rented by the murderer first.

There were still some things in this room. After all, even though the murderer made some preparations, he was forced to leave and inevitably left behind some items, including traces of daily life.

If it were an ordinary suspect, with these items, it would be easy to determine their identity, and then it would just be a typical pursuit and capture operation. There was no need for an expert of Jiang Yuan’s caliber to be involved.

LV5 crime scene investigation is an explosive presence on a national level. Most provincial investigation experts peak at LV3, with only a very few reaching LV4, who are considered top experts in their province. On a national level, those who reach LV5 are rare. In most of the thirty-some provinces and regions, such resources are absent, found only in places like Beijing, Shanghai, Guangzhou, Shenzhen, and Hong Kong, and it’s uncertain where these few might be employed, whether they are touring the nation, or even retired.

Despite how impressive Qi Changye’s department might seem, even the most elite department has limited resources, and this includes human resources.

In fact, because they do not handle social case investigations and do not conduct as many scene investigations as the police, they simply cannot afford to maintain especially elite scene investigation experts. At most, they borrow them when needed.

Experts at the LV5 level would not let their talents go to waste. It’s difficult to keep such experts without utilizing them, just like Jiang Yuan in Ningtai County. If Huang Qiangmin didn’t proactively offer his services, sooner or later, someone else would no doubt borrow and lose him.

The murderer rented an apartment. The first four floors downstairs were a shopping mall, with an old-fashioned tower above with over twenty floors.

The location of the apartment was excellent, situated in the center of the local commercial district, where daily necessities were within walking distance. However, the composition of the building was complex. From the shopping mall on the lower floors to the apartments above, as long as one found the elevator, access control was almost meaningless—too many people were coming and going, and one could simply follow the others.

The division of 36 households served by 6 elevators also made the building’s security almost non-existent. Correspondingly, it was incredibly difficult to collect DNA and fingerprints from the corridors or elevators.

It was somewhat better inside the room. With almost a hundred square meters, it had two bedrooms and one living room. In the living room, there stood an astronomical telescope, its lens facing the balcony of the victim’s residence. Of the other two bedrooms, one had a window with a view of the target, and the other was used as a tool room, containing a long table with at least a dozen different tools and two iron racks holding some scattered parts.

"When the victim Zhang Xuanting smoked, he used to open the window, and he had the same habit when using e-cigarettes. The murderer probably observed this habit and chose to rent a room here," Qi Changye said as he followed Jiang Yuan into the room, summarizing the situation so far.

"Better than using a sniper rifle in the movies," Jiang Yuan commented, looking at the tripod-equipped telescope and feeling slightly immersed.

"To be honest, explosives are much more reliable than a sniper rifle. Hmm, the murderer seemed to have assembled explosives here. He took away the explosives, but from the remaining tools, we can still discern his actions," Qi Changye said with a sigh, adding, "So we have to catch this person fast."

Jiang Yuan nodded silently. The murderer’s target was clearly not Zhang Xuanting; rather, Zhang Xuanting was merely a step towards that target. Eliminating him was more likely an act to buy time to achieve the real objective.

Therefore, the main purpose of the murderer staying in this room was probably to assemble the explosives. Monitoring or killing Zhang Xuanting was more of a secondary task.

In some sense, Zhang Xuanting was more like a fuse. Once it burned out, the murderer knew it was time to leave.

"So, the murderer assembled the bomb in this room, and due to some opportunity, decided to eliminate Zhang Xuanting," Jiang Yuan surmised as he walked to the windowsill, gazing out at the dark night sky and the bright lights. After pondering, he continued, "The murderer used a remote control device to blow up Zhang Xuanting on the spot while he was vaping. Then, the murderer tidied up and swept this room, went downstairs to the opposite side, cleaned up Zhang Xuanting’s home, and then set it on fire before leaving?"

Jiang Yuan’s guess was somewhat akin to a crime scene reconstruction model, only extending the scope of the crime scene.

Qi Changye nodded slightly, saying, "It’s possible."

"But isn’t it overkill to blow a person up and then set fire to Zhang Xuanting’s home?" Jiang Yuan asked in return.

"Not really. Zhang Xuanting was a habitual thief and very cautious in his actions. Even though the house he lived in was rented, he had changed all the locks, and the murderer broke in using force," Qi Changye explained, concerned that Jiang Yuan might not understand, and added, "When murdering someone indoors, if the victim is prepared, it can be quite dangerous. Life is precious; no one truly likes to take risks."

"So, it’s like how predators hunt, always aiming for a kill without injury?" Jiang Yuan somewhat understood.

"That’s the general idea. The area the murderer could observe was limited, so it’s hard to say if there were other preparations inside," Qi Changye paused for a moment before adding, "Also, the murderer might have wanted to confirm the death and possibly took something away..."

At this point, Jiang Yuan agreed, "The explosive power of the e-cigarette might not have been enough to kill him."

As they talked, Jiang Yuan began to photograph everything from beginning to end, then started to inspect bit by bit.

This scene, of course, had already been combed through once. Frankly, Jiang Yuan had rarely been present at an initial crime scene as most experts faced a similar issue. Because they were always traveling around the country, they often saw evidence that the local police had already gone over once, which naturally increased the difficulty by more than a notch.

Some serial killers were caught exactly by such experts. After committing multiple crimes without being detected by the police, they would act again in a short time, only to fall directly into the hands of experts who hadn’t yet left the area. The crime instantly shifted from cold to current cases, leading to a swift arrest...

"We’re finished here; let’s go downstairs," Jiang Yuan said after spending more than two hours scouring the apartment of less than 100 square meters.

Qi Changye had been waiting impatiently for a while but dared not to rush, and now he finally asked, "Did you find anything?"

"Now, the problem is, even if we manage to confirm the killer’s identity, it is very likely a false one. With this, conventional measures used to identify a person, such as DNA and fingerprints, are useless."

Qi Changye was startled, "That’s true. So... do you have a method?"

"We can only let the evidence speak for itself, let’s look further." In fact, Jiang Yuan had some trick up his sleeve, such as the secret weapon he often used, Legal Botany, which can look for characteristics of a specific site. At this moment, it might come in handy.

However, Legal Botany also has its troubles. One is that it’s time-consuming and labor-intensive. If Jiang Yuan started looking for pollen now, by the time he found the place, it could be several days later, which doesn’t fit the current pursuit.

What Qi Changye was hoping for was for Jiang Yuan to simply report a room number and then barge in and rattle around.

As for Jiang Yuan, choosing which pollen to target was the trouble.

If there was a body, there’d be no question, as you’d look for pollen on the body, and most of the locations identified would be meaningful. But in the killer’s residence, which spot or object to choose as the target? It was very likely that after a hard work, one would find a meaningless result.

Therefore, using Legal Botany at this moment was a high-risk, high-investment, high-reward endeavor, and Jiang Yuan did not want to choose it unless absolutely necessary.

The group moved on to the dwelling of Zhang Xuanting, which had been set ablaze.

This was where Zhang Xuanting rented. The renovation, furniture, and everything else were provided by the landlord. The interior was either burned or drenched after a large fire and firefighting efforts, leaving no part undamaged.

At such a fire scene, most evidence would have been destroyed, but the fire scene itself is evidence, including the traces of smoke, burning, spreading, and carbonization, all reflecting the changes at the site. Ordinary fire investigators would do a four-step exploration based on this, namely environmental exploration, preliminary exploration, detailed exploration, and specialized exploration.

As Jiang Yuan proceeded this way, he naturally obtained a series of evidence, but none were decisive.

"I’ll go back and think about it, and check the surveillance again," Jiang Yuan was not in a hurry. In terms of skill level, he was now one of the top experts in the country. The killer had left plenty of clues; it was just a matter of approaching from the right angle.

Plus, he had some tricks he hadn’t yet used.

Qi Changye, however anxious, had no choice but to follow Jiang Yuan.

After all this running around, by the time they returned to the police station, it was already work hours.

Jiang Yuan was also extremely tired, but with Qi Changye watching him with golden-retriever-like eyes and given the special nature of the case, Jiang Yuan managed to perk up, ordered a cup of coffee, and started watching the videos while drinking.

The killer’s regular comings and goings in the apartment could not avoid being captured, front and back photos taken, but the subject was always wearing a mask and sunglasses, making the collected facial information somewhat insufficient.

Jiang Yuan extracted a few pictures and roughly did some image enhancement, but the effect was mediocre.

Just as he watched on and on, and Qi Changye had almost dozed off, Jiang Yuan suddenly woke him with a slap.

"Look at the killer’s shoe cabinet," Jiang Yuan’s eyes were a bit red, but he still looked alert.

"Shoe cabinet..." Qi Changye frowned as he looked at the photos Jiang Yuan was showing and, knowing that he wouldn’t act without purpose, pondered carefully, "Are you talking about the types of shoes? Outdoor shoes, hiking boots, and formal leather shoes..."

"What we need to look at is what’s missing." Jiang Yuan pointed to several empty spots in the shoe cabinet and took out a few more photos, saying, "Look at the several pairs of shoes he wore at that time; none of them are in the shoe cabinet."

"Did the killer take them with him?" Qi Changye immediately thought of the reason and frowned, "He still had time to prepare his travel gear, although taking several pairs of shoes is a bit strange..."

"The shoes he took away were all from Zegna," Jiang Yuan interrupted Qi Changye and took out a stack of printed photos for him, "These are the shoe models I confirmed on the official website. Comparing with the shoe prints confirmed at the scene, the killer took away at least four or five models of this brand’s shoes. It looks like he’s a faithful fan of Zegna shoes."

Qi Changye nodded slowly, "Some people get used to wearing a certain model of shoes and will keep repurchasing them..."

At this, Qi Changye finally caught on, "Do you think he will repurchase shoes of the same brand?"

"It’s better to trace his previous purchases first." Jiang Yuan felt that Qi Changye was still a bit groggy and added, "Even though there are many wealthy people in Beijing, continuously buying several pairs of the same brand of shoes, and size 43 at that, while we know the color and style of four of the models, we should be able to find some information about this customer, shouldn’t we?"

Jiang Yuan pointed to the shoe models in the photo, emphasizing, "As far as I know, luxury brands pay special attention to the long-term behavior of their customers. If someone always buys shoes as a new customer, they probably can only get the more basic styles. If they want popular or limited editions, then their membership needs to be maintained... it’s up to you to see if the brand will cooperate."

Qi Changye smiled without answering Jiang Yuan’s question, just nodding emphatically, "We won’t let him get away this time."