civil forensic

Chapter 1047

Chapter 1047

"This should be the area that Xu Li may have come into contact with. Area No. 2." Deputy Captain Qi Yongmiao pointed out the designated area to Jiang Yuan with a little nervousness.

Jiang Yuan had already obtained the fingerprint of the middle finger of corpse No. 1 by frying it. Now, if he could obtain the same fingerprint from a certain area in the supermarket, it would prove with certainty that Xu Li was the deceased.

A more certain way is to obtain the same DNA, because although the No. 1 body was in a high degree of decay, DNA was still obtained. However, because Xu Li is an orphan and the single room in the house he rented has been rented to other residents, although the investigators also tried to extract DNA, this kind of comparison is actually more troublesome.

In comparison, as a stock clerk, Xu Li can easily leave fingerprints in the supermarket.

While waiting for Jiang Yuan, Wu Junhao and others had roughly demarcated the areas that Xu Li might have come into contact with through the surveillance cameras in the store. However, no identical fingerprints were found in the designated area No. 1.

Qi Yongmiao held his breath at that moment.

If Jiang Yuan hadn't taken the fingerprints himself, Qi Yongmiao would have asked someone to take them again.

Jiang Yuan still looked calm. He also took this matter very seriously, so he came here to take fingerprints in person. Liu Jinghui and others who were traveling with him were observing this small supermarket, and they had already considered Xu Li as the victim and began to think about it.

Area No. 2 is a row of shelves in the warehouse, located relatively far back. From the surveillance footage, although someone else had touched this area after Xu Li, the frequency was not high and the number of times was not large. The key point was that there was no wiping behavior, which is more conducive to preserving fingerprints.

Jiang Yuan took out a gray mouse hair brush, selected silver powder as fingerprint powder, and brushed it finely on the shelf with a black background. The fingerprints were instantly revealed.

Jiang Yuan looked at the fingerprints carefully again and only chose the fingerprint on the middle finger to extract.

It was useless to extract anything else. The only fingerprint that was extracted from corpse No. 1 was the middle finger of the right hand.

The area just collected did not find a suitable fingerprint. Jiang Yuan guessed that Xu Li did not leave the fingerprint of his right middle finger in the area, or left it and it was accidentally wiped off. So, although he did not match, he was not too anxious.

Those who work with fingerprints have all had similar experiences - a confident fingerprint that didn't match. This is something that every fingerprint inspector has experienced. After working in similar jobs for a few years, your mentality will become more stable, or more devastated.

From another perspective, the suspects or victims that the criminal police confidently identified may not really be suspects or victims. Fingerprint and DNA technology not only caught many criminals, but also saved many innocent people.

Many times, coincidences and things that don’t make sense happen in the world. This doesn’t happen often, but once it does, only the purest technology can pull it out of the quagmire.

Jiang Yuan now wanted to use technology to confirm that Xu Li was victim number one. Although everyone, including Jiang Yuan himself, was basically convinced that Xu Li was the victim, there was still a huge gap between certainty and evidence.

There should be such a natural barrier.

Jiang Yuan collected fingerprints on the spot and compared them one by one.

This type of comparison does not require the participation of computer software, and is more like the early fingerprint comparison mode. It is a one-to-one comparison of the similarities and differences between two fingerprints. It is equivalent to the final confirmation step after the software has produced a candidate fingerprint.

Jiang Yuan didn't even need to mark the characteristic points. He had already memorized the fingerprints of the original corpse. Now all he had to do was see if the new fingerprints matched.

In this way, the comparison progressed very quickly. After taking six or seven fingerprints, one fingerprint was left by Jiang Yuan.

At first glance, this fingerprint looks slightly different from the original corpse's fingerprint, but those who are familiar with fingerprints know that fingerprints left on objects are not static.

Because the pressure when the finger touches the object is different, the fingerprint, that is, the pattern on the finger, will be scattered due to high pressure and concentrated due to low pressure. The fingerprint left behind is actually a one-sided fingerprint due to different inclination angles of the contact surface.

If there is a living person present, a full fingerprint can be rolled out, which is easier to compare. Now that the person is dead, it is equivalent to comparing two partial fingerprints. If there is no omission, it will almost have to be a LV2 fingerprint level.

Jiang Yuan was naturally fully covered.

The LV6 fingerprint analysis method, when used in this kind of place, is like a guard who has worked on the island for a year returning home and seeing his young wife.

Jiang Yuan spent a little longer studying the fingerprint in front of him, but it was just to confirm.

A few minutes later, Jiang Yuan straightened up, did not take any more fingerprints, nodded and said: "It is confirmed to be the same, it is indeed Xu Li's fingerprint."

All the police officers present became excited.

This was not just a matter of confirming the identity of victim number one, it also opened up a huge breakthrough in the case.

Liu Jinghui immediately said: "I will contact the technical detective first to see if I can find any clues from the mobile phone number."

Since the murderer sent messages using Xu Li's mobile phone after his death, it means that the murderer was exposed at the time.

However, many of the techniques used by technical detectives are very difficult to guard against in daily life.

Even if the murderer knows how to prevent it, he still has to pay a price. In other words, in order to prevent these things, the murderer needs to make certain compromises, and his actions may be distorted.

Liu Jinghui didn't need to consider how many possibilities there were. Anyway, he would just investigate it first.

Jiang Yuan naturally agreed.

The murderer borrowed the deceased Xu Li's mobile phone to send messages, which in itself is a very important clue.

Liu Jinghui arranged for people to collect surveillance videos from nearby shops and properties, then pulled Jiang Yuan to the side and whispered, "The murderer was very deliberate and must have carefully planned this murder. Xu Li disappeared the day after he received his salary, so it's hard to say this was an isolated incident. However, the murderer was exposed as a result."

"Do you mean?"

"The murderer is likely to be an acquaintance of Xu Li, or at least has a way to get to know him. Therefore, the murder of Xu Li is not a random killing." Liu Jinghui sighed, and then said with shining eyes: "He thought that this would reduce the possibility of being discovered, but it also increased his connection with the victim."

"Xu Li is an orphan." Jiang Yuan said the known situation here, and then slowly said: "He is a supermarket stock clerk, and he probably doesn't have many contacts on a daily basis."

"From the murderer's perspective, the orphan factor might be necessary." Liu Jinghui's thoughts became clearer and clearer, and he said, "The murderer seems to have killed three people in a row, but he might have planned it a long time ago. And if he wants to kill people in succession, he needs the first person, and the second person should be discovered as late as possible. And from his planning, if the victim has family members, once the case is reported, Xu Li will be included in the missing persons database, and the probability of us discovering him will be much greater."

Jiang Yuan nodded without comment.

Liu Jinghui continued, "From the murderer's perspective, he knows so much about Xu Li, so he can't be someone Xu Li is too familiar with, otherwise he would be too easy to be investigated. Therefore, the murderer is most likely not someone with a strong connection to Xu Li."

Jiang Yuan nodded and said, "We just met by chance, and I know a little bit about you."

"Especially knowing when he gets his salary." Liu Jinghui licked his lips and whispered, "This means that the murderer is likely to have communicated with Xu Li in the past two months, either online or offline."

"kindness."

"Then I have an idea."

"Oh?"

Liu Jinghui said: "As a supermarket stocker, I think the number of people Xu Li can contact must be limited, and it will take some time to understand him. I think we can do a screening. Any mobile phone that is in the same place as Xu Li at the same time and lasts for more than 3 minutes will be listed as a suspect. Let's see how many suspects we can gather."