Only by obtaining the DNA information material can the DNA information be stripped and identified, and then compared with the murderer's DNA to identify the real murderer.
This is the current criminal investigation technology, that is to say, the evidence recognized by the court during public prosecution.
The so-called ironclad evidence is to achieve this step.
Yang Lin continued on the phone.
“I isolated a total of three different cells in the mop, which should belong to three different people. Judging from current speculation, one of them should be Wang Lili, and the other should be Wang Hong. , the other one is most likely the murderer.”
There are three types of cells isolated from the mop rod, which is relatively large, and it is also consistent with the situation currently known to the police.
However, there was only one type of cell material isolated from the handle of the kitchen knife, and the parts belonging to Wang Lili and Wang Hong were not isolated.
From this point of view, there should be no problem. After all, Wang Lili should have never touched the kitchen knife over there.
Wang Hong had not used it for a long time. In his impression, the kitchen knife had been idle for a long time after he bought it. It was only used once when chopping bones during the Chinese New Year.
When Wang Hong took the kitchen knife from the refrigerator, she just held the handle of the kitchen knife with her fingers, and there were clear fingerprints on it.
As for the part with fingerprints, Yang Lin did fingerprint identification analysis, so he did not extract the cells from this part.
In this case, there should be only one kind of cell extracted from the handle of the kitchen knife, which is logically correct.
“Judging from the labeling, the third type of cells found on the mop handle and the cells found on the kitchen knife handle should be consistent. After that, I enhanced the DNA information of both cells.”< br>
Achieving this step is a very critical step. Only after this step can we collect DNA information. If this step fails, the above tailoring may be wasted. This step is very important in trace evidence analysis. important.
This is the DNA amplification that Yang Lin, Lu Chuan and others often do.
Generally speaking, the substances collected in trace evidence analysis are very subtle, and some may only be calculated in milligrams.
So on such a small carrier, it is obviously very difficult to extract relevant information about a criminal suspect, especially the other party's DNA information.
In this case, DNA amplification needs to be used in trace evidence analysis, that is to say, the original trace DNA carrier is amplified. Only when the amplification reaches a certain level can the identification and subsequent identification be continued. analyze.
The instrument used here is called a PCR instrument.
The full name of this thing is PCR gene amplifier, PCR nucleic acid amplifier, polymerase chain reaction nucleic acid amplifier.
It is an instrument that uses polymerase chain reaction technology to amplify specific DNA.
In the past, this kind of thing was very expensive, with one unit costing millions.
After the monopoly on related polymerase chain reaction technology was broken in the past two years, the price of this instrument has slowly dropped.
But it’s not cheap either. The one Lu Chuan and the others purchased cost 3.2 million.
The reason why it is so expensive is because DNA amplification instruments have different performance indicators and uses.
Most of the DNA amplification instruments encountered on the market cannot actually be used in the field of criminal investigation.
Those that can be used in the field of criminal investigation are the most high-end and most sophisticated.
Currently, domestic production and manufacturing are not possible and can only be purchased from abroad.
And the reagents used are also very expensive.
Basically, if you use it once, it will cost you 10,000 yuan less.
So don't think this thing is more useful. It's really rude to spend money on it. "Just an hour ago, after amplification, the DNA sequence of the cellular material we found on the kitchen knife handle and the mop handle were completely consistent. I personally think it can be proven that this was what the murderer left behind. .”
Yang Lin finally gave a conclusion.
Good!
Very good!
It can be said that another village has a bright future.
Lu Chuan was still worried just now, and then he caught Zhang Chao. The evidence chain was incomplete. Without irrefutable evidence, there was no way to convict the other party.
As a result, less than two hours later, the criminal investigation team gave Lu Chuan some reassurance.
The following work is very simple. First arrest Zhang Chao, and then take the other person's blood to test the DNA information. As long as it can be successfully compared with the DNA information measured by Yang Lin, then this The case became a solid case.
"Zhao Kai! Arrest people!"
After putting down the phone, Lu Chuan immediately called Wang Zhaokai.
Arrest people?
Wang Zhaokai was stunned. Lu Chuan had just told him to keep an eye on the person first and not to touch him for the time being to avoid knocking down the police car. He had to wait for the technical appraisal results from the criminal investigation detachment.
He did not expect that orders would come from Lu Chuan so soon.
I wanted to ask if Lu Chuan had relevant evidence, but Wang Zhaokai suppressed this idea.
Since the director of Lu Chuan City gave the order to the other party, there must be a reason. As an executive, he does not need to question the leader's decision.
Of course, if the leader above was a loser, Wang Zhaokai would definitely still ask, or even support him, but Lu Chuan was different.
Wang Zhaokai felt the smoothest and most comfortable working under Lu Chuan.
Although it doesn’t mean that you don’t work overtime and don’t work overtime, that’s not what it means at all.
To be honest, working with Lu Chuan and handling cases is quite tiring because Lu Chuan has many cases in his hands.
For example, this case, which was originally a theft, occurred at the Tianshan District Public Security Bureau.
In terms of jurisdiction over the case, it should have been the criminal police brigade of the Tianshan District Public Security Bureau to follow up on this case, and there was no need for our High-tech Zone to take action.
What's more, the High-tech Zone Criminal Police Brigade just solved a murder case here a few days ago. As a result, they didn't rest for a few days, and another murder case occurred.
In the past, I could not meet a sensitive person all year round, and when I did, I would be busy for days, ten days or even months.
But it's good now. Murders seem to be a common occurrence, one after another.
People who work on criminal cases are prone to mental stress, especially when encountering a murder case.
So working under Lu Chuan is really tiring. There are many cases, many business trips, and a lot of overtime work.
But the sense of accomplishment after solving the case is unparalleled.
Handling the case with Lu Chuan went very smoothly. It seemed that no matter what problems they encountered, Lu Chuan could solve them. As long as Wang Zhaokai and the others followed Lu Chuan's ideas, the case seemed to be solved naturally.
And solving murder cases is different from other cases.
After solving every murder case, there are rewards. (End of this chapter)