"This should be the area that Xu Li may have come into contact with. Area No. 2." Deputy Captain Qi Yongmiao nervously pointed out the designated area to Jiang Yuan.
Jiang Yuan had previously obtained the fingerprint of the middle finger of corpse No. 1 by frying it. Now, if the same fingerprint can be obtained from a certain area in the supermarket, it can be definitely proved that Xu
He was immediately dead.
A more certain way is to obtain the same DNA, because although the corpse No. 1 was highly decomposed, the DNA was still obtained. However, because Xu Li was an orphan, the single room in the rented house had been rented to other residents, so the investigation
Although personnel have also tried to extract DNA, this comparison is actually more troublesome.
In contrast, as a tally clerk, Xu Li easily left his fingerprints in the supermarket.
While Wu Junhao and others were waiting for Jiang Yuan, they had roughly delineated the area where Xu Li might have come into contact through the surveillance in the store. However, the same fingerprint was not taken from the designated area No. 1.
Qi Yongmiao held his breath at that time.
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 specially to take fingerprints in person. Liu Jinghui and others who were traveling with him were observing the small supermarket and began to think about Xu Li as the victim.
Area No. 2 is a shelf in the warehouse, located relatively far back. From the monitoring point of view, although there are people behind Xu Li who have come into contact with this area, the frequency is not high and the number of times is not high. The key point is that there is no wiping behavior, which is relatively
Helps preserve fingerprints.
Jiang Yuan took a squirrel hair brush, chose silver powder for fingerprint powder, and then applied it carefully on the shelf with a black background, and patches of fingerprints were instantly revealed.
Jiang Yuan looked at these fingerprints carefully and only selected the fingerprint of the middle finger to extract.
It was useless to extract anything else. Corpse No. 1 only produced a fingerprint of the middle finger of the right hand.
No suitable fingerprints could be found in the area just collected. Jiang Yuan's guess was that Xu Li did not leave the fingerprint on the middle finger of his right hand in the area, or that he left it and was wiped off by mistake. Therefore, although there was no
, and he was not too anxious.
Those who do fingerprints all have too many similar experiences - confident fingerprints are no match. It can be said that this is a situation that every trace inspection has experienced. After doing similar work for a few years, your mentality will be more stable. Or
A little more broken.
From another perspective, the suspect or victim that the criminal police confidently confirmed may not actually be the suspect or victim. Fingerprint and DNA technology not only caught many criminals, but also saved many criminals.
Many innocent people.
Many times, coincidences will happen in the world, and things that do not conform to reasoning will happen. This kind of situation is rare, but once it occurs, often only the purest technology can drag it out of the quagmire.
Jiang Yuan now wants to use technology to confirm that Xu Li is the No. 1 victim. Although Jiang Yuan himself, including Jiang Yuan, is basically convinced that Xu Li is the victim, there is still a gap between the certainty and the evidence.
There should be such a natural chasm.
Jiang Yuan collects fingerprints on site. If you collect one fingerprint, you can compare it with the next one.
This kind of comparison does not require the participation of computer software, and is more similar to 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 step of confirmation when the software identifies candidate fingerprints.
Jiang Yuan didn't even need to mark the features. He had already memorized the fingerprints of the original corpse. Now it was just a matter of seeing if the new fingerprints matched.
As a result, 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 that of the original corpse, but anyone familiar with fingerprints knows that fingerprints left on objects are not immutable.
Because the pressure of the fingers when touching the object is different, the fingerprints, that is, the patterns on the fingers will be spread out due to high pressure, and concentrated due to low pressure. Also due to the different deflection angles of the contact surface, the fingerprints left behind are actually
One-sided fingerprints.
If there is a living person present, it will be easier to compare by rolling out a full fingerprint. Now that the person is dead, it is equivalent to comparing two partial fingerprints. If there are no omissions, it is almost necessary to have LV2
The fingerprints are level.
Jiangyuan is naturally fully covered.
LV6's fingerprint analysis method, used in a place like this, is like an island guard who has been working for a year coming home and seeing his little wife.
Jiang Yuan spent a little time studying the fingerprint in front of him, but it was just to make sure.
A few minutes later, Jiang Yuan straightened up and nodded without taking any more fingerprints: "It is determined that they are the same, and they are indeed Xu Li's fingerprints."
All the police officers present became excited.
This is not only a matter of determining the identity of victim No. 1, but also opens a huge breakthrough in the case.
Liu Jinghui immediately said: "I'll contact the technical detective first to see if I can find any clues from the mobile phone number."
Since the murderer used Xu Li's cell phone to send messages and so on after his death, it means that the murderer was exposed at that time.
Many techniques used in technical investigation are very difficult to prevent on a daily basis.
Even if the murderer knows how to prevent them, 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 deformed.
Liu Jinghui didn't need to consider the possibilities here. Anyway, he would check it out 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 of nearby shops and properties, and then pulled Jiang Yuan to the side and whispered: "The murderer must have planned this murder carefully. Xu Li took the salary
He disappeared the next day. It is difficult to say that this was an isolated incident. However, the murderer was also exposed."
"Do you mean?"
"The murderer is probably an acquaintance of Xu Li, who at least has channels to know him. Therefore, murdering Xu Li is not a random killing." Liu Jinghui breathed a sigh of relief, and then said with bright eyes: "He thought this could reduce the risk of being discovered.
possibility, but it also intensifies the connection with the victim."
"Xu Li is an orphan." Jiang Yuan said the known situation here, and then slowly said: "He is a supermarket tally clerk. He should not have too many people in daily contact."
"Considering from the murderer's point of view, orphans may also be necessary." Liu Jinghui's thinking became clearer and clearer, saying: "The murderer seems to have killed three people in a row, but his plan may have been planned long ago.
He is doing it. If he wants to kill continuously, he needs the first person. The later the second person is discovered, the better. From his plan, if the victim has a family member, once the crime is reported, Xu Li will enter
In the missing population database, the probability of being discovered by us is much higher."
Jiang Yuan nodded noncommittally.
Liu Jinghui continued: "Similarly from the perspective of the murderer, he knew so much about Xu Li that he would not be someone Xu Li was too familiar with, otherwise it would be too easy to be investigated. Therefore, the murderer is probably not a person with strong connections to Xu Li
.”
Jiang Yuan nodded and said: "We met by chance, and we know a little bit about it."
"Especially knowing the time when his salary is paid." Liu Jinghui licked his lips and whispered: "This means that the murderer may have communicated with Xu Li in the past two months, either online or offline."
"kindness."
"Then I have an idea."
"oh?"
Liu Jinghui said: "Xu Li is a supermarket tally clerk. I think the number of people he can come into contact with must be limited, and it will take some time to get to know him. I think we can do a screening and select all people who are in the same place as Xu Li at the same time.
If the cell phone in a location lasts for more than 3 minutes, it will be included as a suspect and we will see how many suspects we can come up with."
