Chapter 156 Someone else
Detachment leader’s office.
Qin Yong is crossing his legs, holding a small teapot, and humming popular songs from thirty years ago.
Homicide is not terrible, as long as you can solve the case, you are a good policeman.
From being a front-line criminal policeman to now, Qin Yong has experienced thousands of cases, large and small.
There are almost a dozen or twenty murder cases every year.
It can be said that he was trained in the mountains of corpses and the sea of blood.
Facing the murder case, Qin Yong has long had a normal mind.
When you are handling a case, you should be nervous and work overtime. Now that the case is solved, it is time to relax.
In fact, it makes sense that a police officer will not live long. When a case comes, adrenaline surges, and it is common to stay up for days and nights.
The case was closed, and everyone seemed to be paralyzed.
Qin Yong was leaning back in the chair, humming a tune, squinting his eyes and about to fall asleep.
Go to the bureau tomorrow to report the case. You can get off work at noon...
Buzzing buzzing.
The vibrating sound of his cell phone woke Qin Yong who was just about to fall asleep.
"Old Liu, are you done at the scene?"
The first crime scene is the most focused part of the investigation in all murder cases.
"We are almost busy here, but we discovered a new situation."
"Oh? What is the situation?"
"Zhang Wei...may not be the murderer!"
Not a murderer?
Liu Guodong's words were like an ice pick, piercing Qin Yong's heart.
The drowsiness I felt just now dissipated instantly.
Jumping up from his chair, Qin Yong’s voice rose an octave higher: “What did you just say?”
Liu Guodong’s voice was low: “Zhang Wei, maybe he is not the murderer.”
Liu Guodong, who was far away in cold storage No. 8, was wrapped in a coat and had cold snot flowing across his nose.
The work on site is nearing completion and will be over soon.
After collecting on-site evidence, you can have a peaceful sleep when you go back.
As a result, a phone call from Lu Chuan meant that all work might have to start again.
"Did you find anything at the scene?"
Qin Yong's first reaction was what evidence Liu Guodong found at the scene.
But Zhang Wei has already given up, and his account of the crime is also very detailed, and it does not look like he is taking the blame for someone else.
“Nothing was found on this side of the scene, it was Lu Chuan’s side.”
“He collected a drop of blood from the body fragments. The blood type did not match the blood type of the deceased. It was guessed that it was Left behind by the murderer."
"Before we caught Zhang Wei, Lu Chuan did a blood stain analysis on Drip's blood type."
"But just after Lu Chuan collected blood from Zhang Wei, he found that his blood type is type A, and the blood type dripping blood is type AB."
"Zhang Wei, it is very likely that he is not the murderer!"< br>
After hanging up the phone, Qin Yong put on his coat and went straight to the current exploration laboratory.
When Liu Guodong called Qin Yong to report, Lu Chuan was collecting DNA information from the blood stains on the corpse.
From a technical point of view, Lu Chuan is only providing evidence of current discoveries.
As for who the evidence points to, that is not Lu Chuan's concern.
So, after determining that Zhang Wei's blood type did not match the blood type of the blood stain, Lu Chuan focused on extracting DNA information from the blood stain.
When Qin Yong arrived, the DNA information from the dripping blood had just been extracted.
"Xiao Lu, Lao Liu said you have made new discoveries here?"
Looking up and seeing Qin Yong coming in, Lu Chuan nodded, and then continued to operate the computer.
Compared with the past few months, Lu Chuan was no longer the newbie who always saluted everyone he met.
Being the first-class meritorious recipient allowed Lu Chuan to accumulate enough status.
Now, no one is talking about the time when Lu Chuan joined the police.
The entire criminal investigation detachment knows that Lu Chuan is an expert in fingerprint identification and analysis.
This is one of the most popular technical abilities.
Maybe one day I will have a fingerprint on my hand and need help. "Team Qin, we have discovered something."
Lu Chuan explained in detail the situation of inconsistent blood type comparison.
“According to Zhang Wei, he killed Wang Guizhi alone, and then dumped the body in a taxi alone.”
“In this case, it is impossible for Wang Guizhi’s body to be Stained with the blood of anyone except herself and Zhang Wei.”
"Then where did this drop of blood come from?"
A drop of blood is insignificant, but sometimes it is enough to overturn the entire case.
What the police pay attention to when handling cases is not the thoroughness of logic.
Logic makes sense, but reality may not make sense.
What happens in reality is not entirely logical.
For example, Zhang Wei's motive for killing, according to his explanation, was that he killed the person because they had a quarrel.
This is obviously illogical.
But reality may happen.
So, in any case investigation, logical reasoning is basically an auxiliary analysis.
The final thing to look at must be the evidence.
The witnesses and physical evidence must be complete, and the chain of evidence must be complete, and there must be no contradictions.
According to Zhang Wei's narrative, the motive for the murder, the murder weapon, the crime scene, the process and technique of dumping the body, etc., can all form a closed loop.
However, the drop of blood on the corpse caused a loophole in the closed loop.
Of course Qin Yong knew what Lu Chuan meant.
The source of this drop of blood must be found.
"How about DNA information comparison?"
Lu Chuan has just entered the information into the system and is comparing it.
When Qin Yong asked, the result just came out.
"Huh?"
Glancing at the report, Lu Chuan was slightly startled: "The information comes from the same source?"
"What information has the same origin?"
Qin Yong took a step forward when he saw the DNA comparison results.
"Oh," Lu Chuan clicked the mouse and printed the report: "When I collected Zhang Wei's blood, I also collected his hair and did a DNA information test."
"Wang Guizhi's corpse The blood stains on the block show that the DNA information of Zhang Wei is homologous, and there is a parent-child relationship between the two.”
Parent-child relationship?
"When Zhang Wei committed the murder, his son was also present?"
Qin Yong immediately understood what was going on.
"Is it even possible that the murderer was not Zhang Wei at all, but his son?"
"Zhang Wei...is taking the blame for his son?"
Lu Chuan shook his head. These two conclusions cannot be distinguished by technology.
But now that we have this clue, it's not difficult to track it down.
Zhang Wei said that he had been driving before the murder, and you will know if you investigate the trajectory.
And according to preliminary investigation results, Wang Guizhi took the bus home after get off work.
If you check why she got off the bus and took a taxi, you will understand everything.
Taking the report, Qin Yong left the field investigation laboratory and made a phone call while walking: "Zhang Hui, re-interrogate Zhang Wei!"
Lu Chuan packed up the instruments and remaining test materials, put on his coat and left.
The on-site work at Cold Storage No. 8 has not been completed yet, and Lu Chuan can still catch up with the finishing touches.
Interrogation room.
Faced with the DNA information comparison report in Zhang Hui’s hands, Zhang Wei said nothing.
"Zhang Wei, did you kill the person?"
"Don't think that if you don't say anything, we can't do anything."
"We are already looking for the people who were in your car three nights ago to find out whether it was you or your son who drove the car that day. Just ask and you will know.”
While Zhang Wei was being tried for the second time, the arrest of Zhang Wei’s son Zhang Xuanrong was also launched simultaneously.
(End of this chapter)