Coroner Coroner

"But Mr. Lin Xinyi, isn't this handprint a little fuzzy?"

"If you can only see it with a flashlight, there is no way to compare it with the palm of the suspect."

The fingerprints did appear, but they were still not clear.

It is a bit difficult to use this handprint to catch people.

"It's ok."

Lin Xinyi said calmly:

"Let's confirm the attribution of this handprint first:"

"First of all, the handprint printed on the outside of the glass door cannot see the palm pattern, and the person who left this handprint should wear gloves."

"Secondly, it's not a sweat handprint, but a dust-plus handprint."

Dust plus handprint, as the name suggests, is a handprint formed by dust when touching an object with a hand stained with dust.

"The cleaning maids don't have so much dust on their hands, as does the guest manager Yamazaki."

"And the murderer climbed the wall and climbed over the balcony to enter the scene. There must be a lot of dust from the outer wall on his palms and soles."

"Gloves, dust, these two points are enough to prove that this handprint belongs to the murderer."

Hearing this, Zunde Seyu, who was beside him, swallowed nervously.

Indeed, he had just finished climbing the wall and pushed the door open with his gray-stained gloves.

At that time, he didn't see that he had left a handprint, but he didn't expect that the invisible handprint would appear when the boy surnamed Lin took a flashlight.

Elder Seyu's heart thumped up and down like a roller coaster.

He gently wiped the cold sweat from his forehead and sighed inwardly:

"Fortunately, fortunately, it's a handprint with an indistinct outline..."

"Otherwise, there will be big trouble."

He was thinking so in his heart, only to hear Lin Xinyi suddenly speak again:

"Since it is determined that the handprint belongs to the murderer, we can extract it."

"It's inconvenient to just look at it with a flashlight, but if you can extract it in the right way, you can further make it fully visible."

"Once the extracted handprints are obtained, you can compare them with the outlines of the suspects' hands."

"Ah, ah?" Zunde Seyu's expression changed, and he forced his composure, pretending to be curious, and asked, "Without the equipment, can this handprint be extracted?"

Didn't this cost his life!

In his nervous eyes, Lin Xinyi replied:

"The forensics class did not bring equipment to extract fingerprints."

"But... Mr. Seba should have something in your house."

"Eh?" Zunde Seyu was taken aback for a moment: "How can there be in my family."

"Ugh…"

Lin Xinyi sighed slightly:

There was nothing in the forensics class, forcing him to use earthly methods from start to finish:

"Broad tape."

"Just give me a roll of tape that's wide enough."

Chapter 58

The tape paper extraction method is suitable for the extraction of dust fingerprints on the surface of smooth objects.

In the case where the contrast between the dust fingerprint and the object is not obvious like now, sticking with tape paper can avoid the influence of the object.

At Lin Xinyi's request, the servants of the Seyu family quickly delivered a roll of wide tape.

The Seyu family has a big business, and the utility room is wider than the living room of ordinary people. This kind of daily clutter is always prepared.

So, in the nervous eyes of Mr. Seyu...

Lin Xin first used his tape to extract the handprints he left.

And the extraction process is very simple...

The principle and operation are probably similar to those of primary school students using tape to remove typos in their workbooks.

Spread the wide tape evenly over the glass, press it hard, and carefully tear it off.

The fingerprint of the dust was completely adhered to the wide tape.

"But...still can't see clearly?"

The police officers asked with concern.

Although the handprint is printed on the tape paper, it is easy to hold, but it is still a little unclear.

"It doesn't matter, did you forget the operation to find the handprint just now?"

"We can also use this light transmission enhancement method, and it is more convenient to operate."

With that said, Lin Xinyi gently placed the wide tape with handprints in front of the black body of the TV in this room.

When the background color is changed, the contrast is more obvious.

The fingerprints on the tape suddenly became much clearer.

"Come on, flashlight, and light it from the side at a 45-degree angle."

Lin Xinyi continued to guide several rookie operations:

This time, when the lights were turned on, the dust fingerprints on the wide tape were more clearly revealed against the black background.

Because of the particle nature of the dust, the dust fingerprints are opaque and diffusely reflective, and the tape that sticks the dust fingerprints has better light transmission.

Therefore, when the light source is irradiated at an angle of 45 degrees, the part of the tape with dust is in a diffuse reflection state under the irradiation of light, and the part of the tape without dust is in a specular reflection state under the irradiation of light, which greatly strengthens the fingerprint. contrast.

"Now see clearly!" The police officers in the forensics class shouted excitedly.

"Photo record." Lin Xinyi calmly ordered them to do the only thing they were good at.

In this way, the police officers in the forensics class took pictures of the fingerprints, and the wide tape with the fingerprints was well preserved.

"This this…"

Zunde Seyu's expression changed slightly, and then he asked calmly:

"With this handprint, the criminal can be caught, right?"

"It can make a big difference."

"Every person will have a slightly different hand profile because of differences in age, gender, weight, bones, etc."

"Although there is no palm print to accurately lock the identity, by comparing the contour of the hand, at least the scope of the investigation can be greatly narrowed."

Lin Xinyi explained with caution.

"Oh...just narrowing down..."

Mr. Seba's battered heart got a little sigh of relief again.

But he didn't expect that Lin Xinyi was like the master fighting landlord with 17 cards in his hand. Although he had thrown the bomb, the good cards in his hand were far from finished:

"It's a bit reluctant to rely on fingerprints to find the murderer."

"So I will use another method to extract the footprints of the murderer."

"Footprints?"

Several forensic officers asked curiously:

"Can wide tape still find and extract footprints?"

"No, I can't use tape this time." Lin Xinyi shook his head slightly:

The adhesive tape is so strong that it can pick up almost all the dust on the object plane.

And the glass window was cleaned every day by the servants. It was clean and there was no dust.

All dust fingerprints can be extracted from the glass directly with the tape, without being disturbed by other dust.

But the footprints are different.

Footprints can be on floors, walls and marble handrails…

Those places are rougher than the glass and are covered with more dust.

If you use a sticky tape to stick it directly, you will probably only get a piece of tape full of dust in the end.

Therefore, if you want to extract footprints, you must use a method with a higher technological content.

"that…"

Lin Xinyi looked around in the room.

Finally, he set his sights on the square old-fashioned TV:

"Take this TV apart, and remove the black chassis panel on the side of the TV."

"Huh?" The police officers didn't respond:

Why dismantle other people's TVs, TVs can also be used to solve crimes?

"Directly dismantle!"

"I've been demolished... er... The Mumu Police Department will pay!"

Lin Xinyi urged without explanation.

As a result, a few young police officers quickly removed the TV.

Zunde Seyu wanted to stop him very much, but he couldn't open his mouth. As a big chaebol, he couldn't even give up a TV.

Soon, the TV was disemboweled.