"Mr. Lin Xinyi, can you find the cleaned blood stains?"

Suzuki Sonoko asked impatiently.

Unknowingly, this young lady who came to "chasing stars" also assumed the identity of the investigator and focused her attention entirely on the case.

This sense of participation has never been experienced before.

Because Lin Xinyi relies on knowledge to solve crimes, rather than relying on his own extraordinary IQ like those famous detectives.

IQ is a gift from God, but knowledge can be mastered by ordinary people.

Therefore, at this moment, even Suzuki Sonoko, as an ordinary person, will have a sense of participation of "I can understand" and "I also understand"——

Instead of the "understood something" and "you understand again" barrier and confusion that I felt when I saw Kudo Shinichi solving a case in the past.

“Won’t the blood be washed away by water??”

Like a studious student, Suzuki Sonoko added.

"It's just clean on the surface."

"After the blood is washed, there will still be an imperceptible trace amount remaining, and through scientific means, such as the luminol reaction, we can find it."

Lin Xinyi explained:

Luminol, also known as luminol, emits blue light when oxidized.

The heme in the blood can catalyze the reaction between luminol and hydrogen peroxide, showing blue-green fluorescence.

This detection method is extremely sensitive and can even detect trace amounts of blood diluted to one part per million.

Therefore, it is basically impossible to escape the detection of luminol by washing with water.

If you really want to clean up the traces, you must first use strong oxidants such as hydrogen peroxide to destroy human DNA, then wash the scene with animal blood, cover it up, and finally wash it again with bleach.

The prisoner fled the scene in a hurry and was trapped on the platform immediately. He absolutely did not have the conditions to clean up the traces so thoroughly.

"Luminol..."

Kudo Shinichi on the side reacted belatedly:

"Yes...there is indeed such a thing."

"But it seems that I have never seen it used by the Metropolitan Police Department..."

He suddenly remembered that he had learned this knowledge in Hawaii.

However, so many cases have been solved...neither he nor other detectives, not to mention the police, basically no one has used this technical method.

Unknowingly, this thing was almost forgotten by everyone.

"Um? I've never seen the Metropolitan Police Department use it?"

Lin Xin felt his scalp numb when he heard:

Luminol has been used for blood testing in criminal investigations since the 1930s. Doesn’t the Metropolitan Police still have it?

No... given the level of performance of the Metropolitan Police Department in this world, it is possible that they are equipped but do not intend to use it.

Otherwise, if they can use all the criminal science and technology that the police should have, there will be nothing to do with detectives.

"I hope the Metropolitan Police Department can be more reliable this time..."

"At least the most basic survey tools must be prepared."

Lin Xinyi sighed helplessly in his heart.

Then, having made plans to test the blood using luminol reaction, he, Kudo and Sonoko walked out of the crime scene and came to the platform outside.

Only then did Lin Xinyi discover...

The real difficulty in investigating the case does not lie in the technical equipment, but in the people, the more than 100 people who were forcibly left to cooperate with the investigation.

As soon as Lin Xinyi and the others came out of the restroom, the waiting passengers who were guarded on the platform and were not allowed to leave immediately looked over:

"Come out, come out!"

"Have you found out who the murderer is?"

More than a hundred pairs of eyes looked over at him, almost all of them filled with impatience.

"Um...not yet."

"But we have found a way to identify the murderer. When the technical personnel from the Metropolitan Police Department come, we will be able to find out who the murderer is."

The one who stood up and spoke was Kudo Shinichi. He was more famous and had more prestige in front of the masses.

But this time, even the great detective's prestige has no effect:

"What? Wait until someone from the Metropolitan Police comes over..."

"Did Kudo Shinichi not find the murderer at all?"

Everyone was disappointed, and the reputation of the famous detective Kudo Shinichi was damaged again.

In the imagination of these passengers, with the "Heisei Sherlock Holmes" around, it should take less than a few minutes to find the murderer.

Therefore, when they feel that the case will be solved soon, they will wait patiently until now.

But now, the savior of the Japanese police said that he had not found the murderer and had to wait for the Japanese police to come over before starting the investigation.

Just kidding...The savior has not been found, so the one who is saved can do something?

"Can those freeloaders really find the murderer?"

"How much time will it take to wait for those useless police officers to come over and slowly investigate the murderer?"

"If we can't find them again...are we going to keep more than 100 of us detained?"

The passengers waiting for the train started shouting in confusion.

The matter is not of their own concern, and the life pace of metropolitan citizens is generally tense, and they are not willing to waste too much time because of a dead person they do not know.

Whether the murderer can be caught or not has nothing to do with them, but if they delay their afternoon work because of this incident and are penalized by the company, that would be a truly unacceptable event.

"Hey hey..."

The tone of the passengers became heated again:

"Just tell me, when will this be finished?"

Kudo Shinichi was speechless and could only turn to Lin Shinichi for help.

Lin Xinyi stood up and said in a calm tone:

"One afternoon, one afternoon should be able to solve it."

Luminol reagent is actually a mixture of luminol and hydrogen peroxide, which must be prepared on site in proportion before use.

However, the luminescence produced by the luminol reaction is extremely weak, and the light generally only lasts for a few seconds, making it difficult to observe with the naked eye. A curtain must be set up to block the light source, and a darkroom must be arranged before it can be used.

After doing these preparations and checking more than 100 people one by one, the result can still be conservatively estimated in one afternoon.

But as soon as these words were said, the passengers became even more unstable:

"It takes so long in one afternoon?"

"Hey... I don't want to wait any longer! Anyway, I'm not a murderer, so let me just go!"

Some people have already begun to make a fuss impatiently.

"Yes! There was a detective here before, and I thought it would be solved in a few minutes."

"Now we have to wait for the Metropolitan Police Department to come over, and the time has turned into an afternoon - can it really be solved in an afternoon? We will not be detained until then!"

More and more people echoed, and the atmosphere at the scene became tense.

Judging from their posture, it seems that they want to leave directly and forcefully.

"Mr. Kudo, Mr. Lin."

At this time, the tram station staff responsible for maintaining order came over with an ugly expression:

"Why don't we forget it...there are so many people who can't stop us."

"If they lose control and start a conflict, we cannot bear the responsibility."

"This..." Kudo and Lin Shinyi were helpless.

Indeed, it is no small matter for more than 100 people to start a fight.

No unit is willing to take the responsibility of stimulating group conflicts.

Not to mention the staff at the tram station, even if the Metropolitan Police comes forward, they have to let you go in such a situation.

Although Xiaolan's force is very intimidating, everyone knows that this little girl cannot really hurt anyone.

"How about letting it go?"

"If this continues, something will really happen."

The staff member asked again. He obviously wanted to get rid of this hot potato as soon as possible.

In this way, the passengers wanted to return to freedom, the staff wanted to avoid risks, and only four people, including Lin Xinyi, Kudo, Xiaolan, and Sonoko, were still thinking about the deceased.
To be continued...