Coroner Ke Xue

Lin Xinyi came to this conclusion, then stood up suddenly and searched the bathroom carefully.

Sure enough, without much effort, he found a bucket from the corner of the bathroom.

That's the plastic bucket that cafe employees use to clean up.

When I looked closer, I saw that there was still a small half bucket of bleach that had not been drained out at all.

"It seems that the murderer poured bleach into the bucket and then soaked the deceased's hand in it."

Lin Xinyi said this and looked at the bleach bottles on the ground beside him:

"As for the bleach, the murderer probably got it locally, from the bathroom."

"Bleach is a common toilet cleaning product in the bathroom. The murderer probably saw the bleach placed in the corner of the bathroom during the murder and remembered to use it to clean the traces."

He analyzed it in detail like this, his brows getting tighter and tighter.

Mao Lilan on the side thought carefully for a while, and then asked in a somewhat confused manner:

"Mr. Lin, I remember you said that bleach seems to be useful."

"Can be used to damage DNA."

Lin Xinyi frowned tightly:

"The main component of bleach is calcium hypochlorite. After it is mixed with water, it reacts with water to form hypochlorous acid."

"Hypochlorous acid generates free radicals, and excess free radicals, especially reactive oxygen species, can attack almost all biological molecules, including DNA."

"Specifically, free radicals will destroy the base modification of DNA molecules and cause DNA single/double strand breaks."

"Anyway, if the murderer had washed the deceased's hands with bleach and soaked them for more than a certain period of time."

He paused slightly and his tone became more serious:

"Then we probably won't be able to detect enough DNA fragments to support the identification results from the contents of the deceased's fingernails."

Hearing this, Mao Lilan's expression quickly became more solemn than Lin Xinyi:

Even the DNA has been destroyed, doesn’t that mean there is no evidence to catch the murderer?

What to do?

But seeing her nervous and serious expression, Lin Xinyi smiled and shook his head:

"Don't be too nervous."

"Even if the biological test materials in the nails were destroyed, wouldn't there be other evidence?"

"When the murderer squeezed the deceased, their bodies were close together."

"In addition to fingernails, it is also very possible for hair and dander to rub against each other's clothes."

"And those marks are not visible to the naked eye of the murderer."

After saying that, Lin Xinyi said particularly meaningfully:

"Not to mention."

"The murderer worked so well to clean up the traces, but there is no more than three hundred taels of silver left here."

"This" Mao Lilan reacted quickly.

She recalled the confrontation with Tanaka Tomoshi yesterday and immediately came to a conclusion:

"This case was also committed by an acquaintance?!"

That's right, in random robberies and murders, few people will deal with traces after the murder.

Especially in public places like cafe bathrooms.

After all, the murderer did not know the deceased. Even if DNA was left at the scene, it would be difficult for the police to find him in the huge crowd.

But it is different when acquaintances commit crimes: they are often closely related to the deceased. In order to prevent the police from investigating them, they would like to clean the scene cleaner than a dust-free operation room.

And this is often self-defeating.

Because the act of cleaning up traces will inevitably arouse the suspicion of the police, and when the police target a certain person, that person is not far away from a life of clothing, housing, food and drink.

After all, human wisdom has its limits.

No matter how careful a person is, there will always be omissions that he cannot notice.

"Miss Maori, you are right. This case was probably committed by an acquaintance."

"Next, as long as we investigate the deceased's social relationships, it shouldn't be difficult to identify the suspect."

Lin Xinyi praised Mao Lilan for his quick reaction without hesitation:

"but."

"But as forensic scientists, we can never make preconceptions."

There is no need for Lin Xinyi to emphasize it. Good student Mao Lilan has already completed the answer:

"I know, Mr. Lin."

"The current facts of the case point to an acquaintance committing the crime, but the possibility of robbery, homicide and impulsive homicide cannot be completely ruled out."

"To rule out the possibility of the latter, we have to carefully observe the situation at the scene."

As he spoke, Mao Lilan carefully looked at the narrow and crowded toilet cubicle, and soon turned his attention to the window on the wall of the cubicle.

The window is open, allowing access to the outside world from this compartment.

"When we found the body, it was against the door, blocking the door from the inside."

"So, if the murderer kills people in this toilet cubicle, then there are only two ways for him to leave the cubicle after killing people:"

"One, escape directly outside the coffee shop through the window in this compartment."

"Second, climb out through the gap between the top of the cubicle and the ceiling, then leave the bathroom and leave from inside the cafe."

"But, this is the first possibility."

While Mao Lilan was analyzing this to herself, she moved to the narrow window and carefully observed the dust on the edge of the window:

"This first possibility is no longer possible."

"The dust accumulated on the edge of the window has not even been wiped. The murderer definitely did not leave from here."

"And this window is very narrow, so it would be easy for a girl like me to get stuck even when I climb out."

"If you want to flip out from the window frame without touching it at all, only petite children can do it."

As she said this, she quickly raised her head and shifted her gaze to the top of the toilet cubicle:

"The gap between the top of this compartment and the ceiling is quite large."

"Any adult with a thin body should be able to climb out from here."

"only"

Miss Maori’s smooth observation and analysis finally encountered a difficulty:

"The deceased was stabbed in the heart and the amount of bleeding was so heavy."

"And this bathroom is a small space, so you can't dodge."

"When the murderer drew the knife, there should be a lot of blood on his body."

"And when a person with blood on his body comes out of the bathroom, the employees and customers in the cafe should pay more or less attention."

She carelessly rubbed her chin while she was deep in thought, looking a bit like a famous detective.

But Lin Xinyi pointed out an investigation direction:

"Speaking of blood stains, I did notice something strange."

"First of all, there was blood stains on the door frame at the top of the toilet cubicle that should not have been there."

"Secondly, there is the form of splattered blood in this compartment."

He pointed at the little blood stains in the cubicle that were sprayed almost evenly on the toilet, walls and floor:

"It was a complete blood splatter pattern."

"It was as if there was no obstruction in front of the deceased when the blood spurted out."

"That's weird isn't it?"

"There is only so much space in the compartment. If the murderer had killed someone in this compartment, standing in front of the deceased would have blocked some of the blood that splattered out."

"It is very rare for blood to be sprayed without any obstruction in this kind of murder case that stabs directly to the heart."

The knife penetrated the heart from the front. When the murderer drew the knife, he should have been standing in front of the wound.

But the blood stains at the scene told Lin Xinyi:

When the murderer drew the knife, the person was "not present".

"Not to mention, there is this knife."

Lin Xinyi carefully picked up the knife that was left at the murder scene:

"The splattered blood on the handle of the knife is also evenly distributed, as if it is not blocked at all."

"You must know that the handle of the knife is where you hold the knife. When the blood spurts out, the hand holding the knife should always block the blood."

As he spoke, he frowned slightly and asked Mao Lilan:

"Miss Mori, what do you think?"

Although Lin Xinyi quickly discovered these unusual traces, he did not think of the cause of these strange traces.

After all, the murderer's operations in this world are too fancy.

With Lin Xinyi's overly realist mind, he really couldn't reconstruct the true situation at the time of the crime for a while.

But Mao Lilan is different.

She had followed the great detective Kudo since she was a child, and was used to seeing all kinds of tricks and murderers with all kinds of tricks, and even her imagination became unbridled.

At this moment, after being mentioned by Lin Xinyi, Mao Lilan quickly reacted:

"The blood drops on the door frame of the cubicle were unobstructed and spattered."

"Mr. Lin Xinyi, I understand!"

"The murderer did not kill anyone in the cubicle at all, but threw the body into the cubicle from outside."

Mao Lilan's eyes lit up and she expressed her thoughts:

"The murderer must have strangled the deceased with a rope outside the compartment first."

"After being strangled unconscious, he found that there was bleach in the bathroom, so he soaked the deceased's hands in bleach on an impromptu basis."

"Then he tied the rope to the handle of the knife and stabbed the victim in the heart."

"Then, the murderer threw the deceased's body through the gap above the compartment and blocked the door, creating a 'secret room'."

"Finally, he pulled the rope from outside the compartment and pulled out the knife tied by the rope from the heart of the deceased."

"Uh" Lin Xin was stunned for a moment after hearing this.

After digesting the murderer's fancy killing techniques for a while, he finally understood the murderer's intention:

"I see. If you draw the knife this way, the murderer won't get any blood on him."

"He can just walk out of the bathroom with dignity and blend in with the crowd without attracting attention."

"However." Lin Xinyi still didn't quite understand: "Isn't this unnecessary?"

"Since we've already strangled the person unconscious, why not kill him directly by strangling him? Why bother with another stab?"

"If it's just strangulation, wouldn't there be no need to worry about blood stains?"

"No, that's not right." Mao Lilan was slightly startled.

She worked hard to use her imagination and make extended thoughts based on the various strange murderers she had seen around Kudo before.

"Could it be?" Mao Lilan said tentatively:

"Did the murderer want to use this trick to eliminate his own suspicion?"

"Mr. Lin, look at the gap in the toilet cubicle. It's so big that only thin people can get through it."

"If we follow the murderer's design, we mistakenly think that he killed someone standing in the cubicle and then came out of the cubicle."

"Then our attention will only be on those who are thin, but not those who are strong."

As he spoke, Mao Lilan's voice gradually gained confidence:

"But it's obvious that he was too clever to be clever."

"After we saw through his trick, he revealed more clues about himself -"

"Obviously, the murderer was an acquaintance of the deceased and a well-built guy."