I'm not a genius detective

Chapter 164: Guiding Clues Emerge, Zhang Zhenhua Interrogated

8am.

Zhang Zhenhua's home.

The Criminal Technology Brigade of the Qingchang City Public Security Bureau is the most professional forensic trace evidence team in the city. In an era where the surveillance network is not yet perfect and traditional criminal investigation methods still dominate, the extreme excavation of physical evidence by case handlers is particularly important.

The city bureau's forensic doctors can accurately reconstruct the angle of force at the moment of the crime by examining the shape of the decaying wounds; they can use diatomaceous earth testing to make the rivers where corpses are submerged speak; the city bureau's trace evidence can use scratch marks of less than one millimeter to deduce the forging process of the murder weapon; and they can interpret the suspect's walking posture from a fragmented footprint of less than half a footprint.

In terms of criminal investigation technology, the municipal bureau is significantly stronger than the branch bureaus and leads the development of criminal investigation technology throughout the city.

For example, the trace evidence comparison system that Gao Bingyang mentioned to Han Ling is among the best in the country in terms of testing technology in Qingchang City.

The dye batch of a single clothing fiber, the mineral composition of a speck of dust, and so on, can all become hidden clues connecting cases.

This core capability of making physical evidence speak for itself has made the Criminal Technology Brigade a sharp-edged team in the field of criminal investigation in Qingchang.

At this moment, the sharp knife had arrived at Zhang Zhenhua's home, along with four outstanding police officers from the First Brigade of the Criminal Investigation Detachment.

Neither of the two branch offices participated in this investigation.

"As part of a routine investigation, your husband is involved in a murder case. Please cooperate."

Duan Jingming, the captain of the Criminal Technology Brigade, arrived in person. After explaining the situation to Zhang Zhenhua's wife, he presented a search warrant and immediately ordered his subordinates to search every corner of the room.

At this moment, he was standing next to the shoe cabinet by the door.

"Where is the storage room in your home?" an investigator asked.

"It's...it's on the basement level, there's a sign that says 302 on the door." Zhang Zhenhua's wife was a little confused, and answered subconsciously.

The word "murder case" put her mind in a semi-confused state.

"Could you please provide the key?"

"Okay... okay."

The police officers dispersed, and Zhang Zhenhua's wife stood in the living room, watching helplessly as the police systematically conducted a "sweep" of their home.

The child has already gone to school, and she is all alone at home.

The task force took into account the school hours of the middle school and came to scout the location to avoid leaving a bad memory in the minds of the high school students.

"Hello, who died?" The woman, realizing what had happened, finally remembered to ask.

One of the officers replied, "It's not convenient to talk about it. Sorry to bother you. You can sit down and rest for a while. It won't take up too much time."

In the entryway, Duan Jingming picked up a pair of shoes with his gloved hands and asked, "Are these the shoes Zhang Zhenhua wore last night?"

The woman glanced at it and nodded: "Yes."

Duan Jingming: Are you sure?

Woman: "I'm sure. I was in the bathroom when he came back and saw him change his shoes. He only has three pairs of shoes."

Duan Jingming: "The other pair at home are black sneakers?"

Woman: "Yes."

Duan Jingming turned around: "Take the other pair of shoes back with you!"

Officer: "Yes, sir!"

Two pairs of shoes were put into the evidence bag, followed by Zhang Zhenhua's clothes.

"When Zhang Zhenhua came back last night, was he still wearing the same clothes he left in?" Duan Jingming continued to ask.

The woman answered every question without hesitation: "Yes."

Duan Jingming: "Which one? Did you take it?"

"Wait a moment." The woman went to the bedroom and came back with her coat in her hand. "I didn't take it with me; it's here."

It seems that Zhang Zhenhua changed his clothes and shoes when he was taken away last night. It might be a coincidence, or he might subconsciously not dare to wear them.

Duan Jingming took it and examined it, but couldn't see any bloodstains with the naked eye.

Last night, when Han Ling and Tong Feng from the Gu'an branch came to the door, I don't know if they had confirmed it beforehand.

Han Ling didn't confirm, because if Zhang Zhenhua had bloodstains on him, it would be impossible for him to escape the police checkpoint's inspection, at least not with the naked eye.

He only needed to take Zhang Zhenhua away. At that time, Zhang Zhenhua was not a major suspect. The subsequent work would be arranged by the special task force command center. Professional matters should be left to professional teams.

On the other hand, although the heart is a high-pressure blood pumping organ, blood is very likely to be sprayed out when a knife is inserted into the heart, especially when the ventricle is punctured. Blood is sprayed out at high pressure along with the heartbeat, and the maximum length can reach tens of centimeters.

However, the murder weapon used by the perpetrator in this case was a Western-style chef's knife with a thin blade. The thin blade is designed to ensure precise slicing and dicing. When this type of knife pierces the heart, the myocardial muscle will undergo a strong conditioned reflex contraction, tightly wrapping around the blade.

Even if the knife is pulled out, the contracted wound may temporarily close, just like a door automatically closing. In this case, the blood will not spurt out, but will flow out slowly.

According to the autopsy reports, the scene of death for all three victims was in this condition.

However, the investigation must still be conducted. If even the slightest trace of blood is found, abandoning the investigation would be a major mistake for the task force.

Several drawers in the study were locked, and after searching for a long time without finding the key, the investigators asked Zhang Zhenhua's wife, who said she didn't know. So they decided to break the lock directly.

The drawers were messy, filled with miscellaneous items. When the investigator opened the last drawer, photo albums and yearbooks came into view.

Opening the yearbook, I found entries from junior high and high school, which exuded a sense of nostalgia and were from a long time ago.

The investigator quickly flipped through the pages, then picked up the photo album.

Most of the photos in the album are from junior high and high school, with the last ones being from after marriage, including photos of his wife and children.

After putting the album back, the investigator continued flipping through the pages and finally pulled out an envelope.

Upon opening the envelope and taking out its contents, the investigator's gaze immediately sharpened.

The photo shows a construction site, and the person in it is undoubtedly Li Dechang.

It wasn't a frontal shot; the angle clearly indicates it was taken from someone who was being followed and secretly filmed. The appearance of Li Dechang's photo suddenly brought Zhang Zhenhua's suspicion of committing the crime to 99.9%, only lacking evidence and a confession.

The investigator came out with the photos in his hand.

"Team Leader Duan."

Duan Jingming leaned closer to examine the photo, his expression immediately turning serious: "Continue the search. I'll call Chief Gao."

Downstairs, police officers were busy at the storage room and next to the electric vehicle. The forensic team had thoroughly examined the electric vehicle but found nothing, so they took out luminol reagent and began spraying it.

From the front of the bike to the handlebars, from the pedals to the storage compartment under the seat, everything is covered.

In an instant, a flash of fluorescence appeared in the storage box. The trace evidence inspector immediately perked up and took out a low-light camera to record the location, shape, and intensity of the fluorescence from multiple angles.

“Stains of blood that look like they’ve been wiped away,” the forensic examiner told his colleague.

The colleague nodded in agreement.

Wipe-like bloodstains are a type of bloodstain that forms when a bloody object comes into contact with another object. They are irregular in shape and have blurred edges.

Judging from the direction and force, it was very chaotic.

It is speculated that Zhang Zhenhua probably put the murder weapon inside.

However, the fluorescence reaction was weak and dispersed, indicating that there was very little blood, so little that it might not be visible to the naked eye, suggesting that Zhang Zhenhua must have cleaned it.

The crime scene was located near the river, just a few dozen meters away, which provided the conditions for on-site cleaning.

Of course, reagent testing can only prove the presence of bloodstains, but it cannot prove that the bloodstains are human blood. It is necessary to go back to the municipal bureau for confirmation in conjunction with other tests.

"Report to Team Leader Duan."

"it is good."

They didn't discuss why Zhang Zhenhua brought the murder weapon back; it would have been better to throw it away or burn it along with the van.

The sticks used to attack the victims can also be burned.

That's the investigator's job; forensic pathologists, the job is simply to conduct the investigation.

The killer was under immense mental stress and his psychological state was unstable. It's understandable that he might have acted in a panicked and hasty manner.

Reality doesn't really have that much logic.

As messages were relayed to the special task force command center, Gao Bingyang decided to immediately interrogate Zhang Zhenhua.

This is the first interrogation.

The other members of the task force also learned of the discovery at Zhang Zhenhua's home. Based solely on the photos and the bloodstains inside the electric scooter, it was enough to show that this person was a prime suspect in the murder.

The light at the end of the tunnel is on the horizon.

"The murder weapon was in the electric scooter? If the police officers at the station had searched it, wouldn't they have subdued him on the spot?"

……

"With so many people to investigate, who could possibly know that Zhang Zhenhua is a suspect in this case?"

……

"That's true, but why did he bring the murder weapon back? Couldn't he have just thrown it away or burned it?"

……

“You have God’s perspective. From God’s perspective, every murder case has a more perfect way of being handled, but the murderer always leaves traces. That’s reality.”

trial room.

Wu Bin was still in charge of the interrogation, while Zhang Zhenhua was already handcuffed.

Before the interrogation began, Gao Bingyang walked in first and introduced himself: "I am Gao Bingyang, the head of the Criminal Investigation Detachment of the Qingchang City Public Security Bureau. Zhang Zhenhua, you know what you've done, right? I'll give you a chance first. How did Li Dechang die?"

Zhang Zhenhua showed no surprise at Li Dechang's death, keeping his head down and remaining silent.

"You have one minute to think it over," Gao Bingyang said. "I'll be leaving in a minute. Your case is very serious. To be honest, even if you confess, you won't get leniency. But you have to be brave enough to take responsibility for your actions and leave behind a reputation as a decent man, so that people won't despise you."

Zhang Zhenhua remained silent.

Gao Bingyang fell silent, glancing at his watch and waiting for the time to pass.

A minute later, Gao Bingyang turned and left. There were many suspects who wouldn't admit their mistakes until they saw the coffin, and in his opinion, it was pointless; they were just suffering for nothing.

Being interrogated is no fun. You can't eat or sleep well, and you have to bear enormous psychological pressure. It's easy to have a mental breakdown. It's much better to just go to a detention center or prison and be comfortable. At least you can have peace of mind.

Those wanted criminals who have been on the run for many years and finally choose to surrender have this mentality: the daily pressure is too great, and the loneliness and fear are more terrible than the loss of freedom. It will gradually crush their mentality and lead to mental problems.

Surrendering yourself is a form of liberation.

"You're not going to say a single word? You were quite talkative last night." As the interrogation began, Wu Bin leaned back in his chair and looked at Zhang Zhenhua.

The crime was committed hastily, leaving too many loopholes. The police arrived right after the person died, making timely arrests during the crucial period for solving the case, as all traces were still intact.

"You don't know what we've got, do you?" Wu Bin continued. "Let me put it simply: the photo of Li Dechang in your drawer, the bloodstains in your electric scooter, the shoes you wore last night. Is that enough? This is just a preliminary investigation. You'll be even more desperate in the future, so don't waste your time."

Zhang Zhenhua looked up.

The two looked at each other, and Wu Bin said again, "The longer this drags on, the more comprehensive our investigation will be. We cannot rule out the possibility of questioning your wife and children multiple times. Do you want to see these things?"
When we searched your home today, we avoided your child's school hours, taking full account of the psychological impact on your child. Wasn't that very humane?

These words were not a threat; visiting the suspect's family members is simply a normal part of the investigation process.

If a father becomes a murderer and the child is a minor, according to regulations, the police can provide humanitarian assistance by only notifying the wife. As for the child, the wife can decide for herself to avoid causing serious psychological trauma to the child.

At least, I can wait until I'm eighteen and finish the college entrance exam.

(End of this chapter)