civil forensic

Chapter 220 Two Lines

Sitting in the office of the criminal police brigade in the forward area, Jiang Yuan carefully compared Bai Yuequn's footprints with the bloody footprints at the crime scene, and checked them repeatedly.

Footprints are bad because they cannot identify suspects one-on-one.It can be approached infinitely, but it just cannot be determined.

Otherwise, if it is like a fingerprint, it can be directly used as ironclad evidence to sue.

The footprints of bare feet can be regarded as fingerprints, but unfortunately most of the time, they are not there.

Murderers generally do not kill barefoot.

Although it cannot be 100% sure, from Jiang Yuan's point of view, this degree of coincidence can basically confirm Bai Yuequn's identity as a suspect.

If it has reached this level and it is not the murderer, then this is just another coincidence.

Considering that the third child, Yuan Yutang, is only in his twenties, and a Ding Ding made of a vajra pestle can't make many lovers and rivals in love, and the mouth with a broken leg should offend a limited number of people. Motivated people have to have similar footprints, how low is the probability?

Therefore, when Lei Xin, the captain of the criminal police team who entered the district, said that there were alibi witnesses, Jiang Yuan immediately questioned the witnesses.

It is difficult for physical evidence to lie, but it is too easy for witnesses to lie.

However, this is also the first time he has encountered such a situation, and he is also a little doubtful.

What if?
Just as Jiang Yuan was frowning and studying the footprints, Huang Qiangmin walked over with a smile.

"Can't figure it out?" Huang Qiangmin looked at Jiang Yuan.

"It's not that I can't figure it out, but..." Jiang Yuan didn't know how to explain it to Huang Qiangmin.

"I don't know much about technology, and I don't know much about footprints. However, according to what you mean, Bai Yuequn's footprints are very consistent with the footprints of the scene?" Huang Qiangmin asked.

"Yes." Jiang Yuan pretended to be full of words, and continued to say: "The height is the same, and so is the height-increasing shoes. The shoe size is also the same, and the same is true for wearing big shoes; there are also weight and age; I also watched the surveillance video Here, his stride and gait are basically the same, if it is a stranger..."

Huang Qiangmin suppressed Jiang Yuan's waving arm with a smile, and whispered: "No need, it's him."

"Ah?" Jiang Yuan was a little surprised. To be honest, he didn't dare to be so sure.

"It was the CSI effect you told me before, but I think you have a little bit of it now." Huang Qiangmin smiled and said, "You must have DNA and fingerprints to determine the murderer? Do you have to be 100% sure to sue? If this is the case, how could we still engage in cases 20 years ago?"

Jiang Yuandao: "So at that time the confession was heavy?"

"Confessions are not 100%, and inducing confessions is not an American patent." Huang Qiangmin waved his hand and said, "There are already enough clues."

"Captain Lei..."

"He is new to the case and doesn't know much about the case. Moreover, the case happened in his jurisdiction, so he must have thought more about it. Don't pay attention to him now."

"That……"

Huang Qiangmin said: "Don't stare at the footprints now."

"Then what?"

Huang Qiangmin said: "You can look at anything. There is a saying in our criminal investigation that a single evidence cannot stand. In my explanation, that is, after the case is completed, there must be more than one piece of evidence. Now, we have actually finished the most difficult part. That means the murderer has been found, and now we have to prove it."

Huang Qiangmin wrung his fingers and continued: "Assuming that the person was killed by Bai Yuequn, let's assume that his alibi is false. The key is, can we prove it? Can we lock him with physical evidence."

Jiang Yuan immediately pulled out from the horn.

Indeed, the murderer of this case left behind a lot of evidence. As long as these evidences can be linked to Bai Yuequn, the case will be solved.

Assuming that someone is a murderer and then proving that he is a murderer is also the most commonly used method in criminal investigation.

In fact, this is the case in most cases.It's still the same sentence, an experienced criminal policeman can sneak out the murderer who killed him for the first time just by looking over.

Therefore, burglary is often more difficult to break than burglary and murder--easy burglary is caused by the suspect's lack of seriousness and insufficient preparation.There are also some professional thieves who have not been caught for a long time, and they are easy to be careless and negligent. In addition, the business intensity is high, and they are easy to make mistakes.

The case of killing wives in Hangzhou, and many other cases of killing wives and killing husbands, are all in the same situation.

Most of the time and energy of the police is used for argumentation.

Yuan Yutang's murder case is not complicated at all.

Assuming that Bai Yuequn was the murderer, he just did some suspicious things.

He changed the shoes he didn't wear often, and he was not injured at the scene, and there was an alibi, but doing this itself involved a lot of work.

And the more you do it, the easier it is to make mistakes.

The easier it is to lock the evidence.

Jiang Yuan couldn't help recalling the autopsy scene a few hours ago.

Both Yuan Yutang and his ex-boyfriend were stabbed to death with the same double-edged dagger.The blade part of the dagger is very long, at least about 30 centimeters in length, and the blade surface is sharp. The most powerful thing is that after a total of more than 30 knives, the sharpness of the dagger has not been reduced.

Such a good quality would have been an absolute magic weapon in ancient times, and even in modern times, it would be an expensive military dagger.

However, in the domestic environment, it is easier to leave clues about such a dagger whether it is easy to buy or not.

The murder weapon: Military dagger.

Jiang Yuan wrote these two words in his notebook and underlined them.

Huang Qiangmin nodded and said nothing.

He also saw the autopsy report.The military dagger also explained why the murderer killed two and stabbed dozens of times without being injured.

Many novice murderers may not have even killed chickens before killing, at least they have not slaughtered medium and large mammals, so they don't know how much resistance the human muscle tissue has.

Things like daggers or short knives are completely different from spears and broadswords.

The reaction force of a dagger or short knife is greater. When the technique is wrong, the wrist and tiger's mouth will bear huge pressure.

The big knife and spear will be practiced for novices for a while, and novices can gather all their strength to slash and stab. Daggers or short knives will not work. Moreover, civilian items will not be so sharp after being stabbed a few times. It is easy to hurt yourself.

In addition, killing people is still very tiring.

To be more precise, stabbing someone with a knife is exhausting.

It's like slaughtering pigs in the village, requiring several big men to hold them down, tie them up, and struggle.

……

One knife, two knife, three knife is okay, more than 30 knife is not so easy.The subsequent movements are deformed, and the probability of making mistakes or injuring yourself will increase.

The sharpness of military daggers can partially solve this problem.

Coupled with the calluses of Bai Yuequn's hands, he has obviously practiced... Jiang Yuan even suspected that he had been prepared for a long time.

key!

Jiang Yuan wrote these two words on the notebook again and underlined them again.

Yuan Yutang's door lock was not destroyed, and there was no trace of technical unlocking. Therefore, the murderer opened the door with a key. While Yuan Yutang and her boyfriend were asleep, he first stabbed his boyfriend to death, and then stabbed Yuan Yutang several times, causing him to die. .

This is also one of the reasons why the list of suspects is dominated by the relationship between lovers and rivals.

No matter how many people Yuan Yutang worked with, he still couldn't get the keys to his house.

Only lovers or rivals are better equipped with keys.

Bloody coat.

Jiang Yuan immediately thought of the murderer's killing process.

The murderer's follow-up to the crime scene was relatively rough, perhaps because he was in a hurry, and the bloody footprints were ignored at all, and the way to eliminate the traces was to pour a basin of water over them.

But with the amount of bleeding at the scene, the murderer's clothes must be stained with blood.He himself can take a shower and change clothes in the bathroom, but it is difficult to clean the changed clothes in one day.

Most people either throw it away, burn it, or bury it.

But either way, it takes time.

Bai Yuequn still lives in the city center, and some of them are under surveillance.

Therefore, the place where he can put the blood coat is very limited, maybe in the bar or the office.

Auditorium monitoring!
Jiang Yuan couldn't bear to write here again.

The monitoring of the theater projection hall is quite important, and it is impossible for it to be broken for a long time. If it happens to happen when Bai Yuequn is watching a movie, the probability is very low, so it is worth checking.

After writing this, Jiang Yuan's confidence came back again, and he said: "I think we can start from the bloody clothes, call in a police dog, and search in Bai Yuequn's bar."

Huang Qiangmin said: "It smells too strong there, and the big Zhuang tune was used by Liu Jinghui, so let's hire someone."

"That's two lines, look for the murder weapon and the bloody clothes, and check the surveillance in the theater's projection hall." Jiang Yuan summed it up, and then asked: "Do you want to communicate with Captain Lei?"

"Let me chat with him. He should have come to his senses by now." Huang Qiangmin smiled, and went to arrange staff.

Jiang Yuan looked at the notes in front of him and fell into deep thought.

(End of this chapter)