Lin Xinyi immediately returned to the big tree that had been visited by the bear before.

Under his orders, Director Tsunoda had already led a group of police officers to conduct a comprehensive carpet search around the big tree.

"How's it going, did you find anything?"

Lin Xinyi asked straight to the point.

Since this tree has been visited by at least one person and one bear, it is very likely that there will be more traces left by human and bear activities in this vicinity.

In the current situation where the investigation is mired and stagnant, even one more trace can be found, which will be of great help to the detection of the case.

Therefore, Lin Xinyi focused on arranging manpower to carry out reconnaissance near this tree.

At this moment, in the face of his inquiry, Director Tsunoda, who was in charge of the survey, became more and more displeased.

The kind of work that is not good at work, and is still holding his breath in front of the leader but does not dare to attack, is very similar to the old fritters that Lin Xinyi encountered in the identification class before.

"Nothing was found except a few bear hairs."

"Supervisor Lin, what are you looking for?"

Director Tsunoda muttered without complaint.

"Shells." Lin Xinyi gave an astonishing answer: "Have you found bullet shells, warheads, bullet holes and anything like this near this tree?" ”

"This..."

Not only Director Tsunoda, but all the police officers present were shocked:

The management of firearms is also extremely strict, and if a case involves firearms, the nature of the case is completely different.

Of course, in this world... Criminals can make several tons of explosives, and from time to time they will blow up a building to add to the fun.

It's just a small gun-related case, and it doesn't seem to be worth making too much fuss about.

"But... Officer Lin, why do you want us to look for bullet casings? ”

"Has anyone shot here?"

"Hmm." Lin Xin nodded: "I suspect that someone has shot here." ”

"Because judging from the height and shape of the claw marks, the brown bear just climbed up a little bit and gave up."

"Predators don't give up their prey that is about to reach their mouths for no reason."

"And there was no trace of a fight at the scene, and the guy who was chased by the bear and fled to the tree probably didn't have the ability to beat an adult brown bear away with his fists, feet, and clubs alone."

"So...," Director Tsunoda almost wrote his doubts on his face, "You think that man has a gun in his hand, and he shot the bear away?" ”

"That's too far-fetched, isn't it?"

Such an argument is indeed far-fetched.

Lin Xinyi will make such an inference, more because of what he has just found on the dirt slope footprint:

The deceased was at least 3 or 40 meters away, and was frightened by his pursuers and hastened his escape.

What could scare her from afar?

It should be a gun.

Since the pursuer has a gun, will this mysterious person who was blocked by a bear in a tree but was inexplicably "let go" by a bear also have a gun?

Could they be the same person?

Lin Xinyi had a series of conjectures in his heart.

"Director Tsunoda, as you said, my conjecture is too far-fetched."

"So, I have to find a way to test this conjecture."

Lin Xinyi calmly admitted the problems in his reasoning.

But at the same time, he asked:

"Is there really nothing to be found near this tree?"

"Nothing!"

Director Tsunoda replied helplessly:

"Not to mention the shells, warheads, bullet holes, there is not even a trace of blood."

"You said that the man might have attacked the bear with a gun, and that bear should have dropped some blood on the ground when he was shot, right?"

Lin Xin was silent for a while.

He didn't doubt the authenticity of Director Tsunoda's answer, nor did he question whether there was anything missing from their survey.

Because when he was arranging the survey mission before, he specially asked Hattori Heiji to stay at the scene as a "supervisor".

With the baby son of the top boss of this top boss, these grassroots police officers can't perform actively, how dare they cheat and play tricks.

"No blood, no cartridge casings, no bullet holes ..."

"Am I wrong?"

The thought flickered.

"No... There is one more basic survey work that has not been done. ”

"Smoke reaction—"

"If the mysterious man did shoot in the tree, there must have been shooting residue on the bark of the tree."

"It doesn't matter if I didn't find the shells or bullet holes, as long as I can detect the remnants of the shot from the trees, it will prove my suspicions!"

.................................

After a long time, support from the Osaka Prefectural Police Headquarters finally arrived at the scene.

They brought the survey tools that Lin Xinyi needed.

It is very simple to check the smoke reaction, and even the identification classes in various places where the crotch is commonly pulled will be equipped with test strips to test the smoke reaction.

This test strip replaces nitrate with a metal compound that is more reactive than nitrate, producing a noticeable color change.

Lin Xinyi had already taken the corresponding bark samples from the trunk, crown, branches and other parts of the tree, numbered, recorded, and preserved.

Spray organic solvents such as ethanol and acetone on the bark to be tested, soak it, and then contact it with test strips...

The results were not long in coming:

"Shooting residues have been detected on the bark—"

"Someone did shoot at this tree!"

Lin Xinyi got the answer he wanted.

Merely...

"It's still weird..."

After getting the results of the successful test, Miss Maori, who assisted Lin Xinyi in the gunpowder reaction test, was a little entangled:

"The mysterious man had shot, but we couldn't find the shells, bullet holes, and bullet heads near the scene."

"Where are all these traces?"

"If you shoot at the ground, there should be bullet holes and bullets on the ground."

"If it was hit on a bear, there should be traces of bear blood at the scene."

"Could it be... Did he shoot the bear in the air and scare the bear away? ”

"But then, we should at least find the shells thrown under the trees, and the warheads that fell from the sky, right?"

"Could it be that these were cleaned up by that mysterious person afterwards?"

Mao Lilan pondered for a while, not only did he not come to any conclusion, but he turned himself around more and more hesitantly.

And unlike her, Lin Xinyi's eyes are particularly clear:

"Miss Maori..."

"I already know why there are no shells, bullet holes and warheads at the scene."

"First of all, I can be sure that the mysterious man is not firing a warning shot into the sky."

"He was standing on a tree and shooting down."

He paused slightly, and methodically gave the proof:

"Didn't you notice..."

"This time, I took samples of the bark from various parts of the tree and tested the smoke reaction in turn."

"One of the pieces of bark taken from the canopy of a tree was also detected with shooting residues."

"What does that mean?"

A word woke up the dreamer, and Mao Lilan, who had been entangled before, quickly reacted with a bright eye:

"When a gun is fired, gunpowder smoke is supposed to be sprayed at the rear of the gun."

"If the remnants of the shot can be detected even at the top of the tree, it only means that the mysterious man is shooting downwards, not upwards."

"That's right."

Lin Xin nodded and said step by step:

"Moreover, I can also be sure that the murderer used a revolver."

"This..."Mao Lilan was a little surprised: "We haven't even found the bullet casings and bullets, Mr. Lin, how did you confirm the type of gun?" ”

"It's the same thing."

"By detecting the shooting residue in the bark samples at each site, we can also confirm the distribution range of the shooting residue."

"Unlike other guns, the revolver shoots out a wider range of shooting residues."

The automatic firearm on one side, due to the relatively closed firearm structure, will have a smoke spray shape, which will appear in a backward and downward semicircle.

However, because the revolver is fired with an open magazine, its shooting residue will be sprayed backwards without hindrance.

Therefore, the shape of the gun smoke spray of the revolver takes on a backward "umbrella shape", and the area covered by the distribution of shooting residue will be wider.

"So, I'm sure the mystery man is using a revolver."

"And because it was a revolver, we didn't find a shell case at the scene—"

"Revolvers don't automatically drop shells, they stay in the magazine after firing, and they can be easily collected, cleaned and taken away from the site."

"Then, this mysterious person looks very suspicious."

"If he was forced to shoot back by accident when he encountered a brown bear, then why did he deliberately clean up the scene and take away the bullet casings left behind after the shooting?"

"Isn't it... What else did he do badly before he encountered the brown bear, so he didn't want to leave a mark and let people know that he was here? ”

Lin Xinyi's tone became more and more solemn.

In his eyes, the mysterious man and the murderer who pursued the dead have become more and more equated.

But Mao Lilan didn't have the heart to follow his train of thought.

She still has unanswered questions:

"Mr. Lin, since you have determined that the mysterious man was standing on a tree and shooting downward, why didn't we find a bullet or bullet hole on the ground?"

"Even if he cleans the warhead, it is impossible to clean up the bullet holes on the ground without leaving any traces."

The traces of turning and filling the soil are very obvious.

If the bullet had hit the ground downward, it would not have left no trace.

"Since there are no bullet holes in the ground, and there are no tree roots, and you can be sure that the murderer shot downward..."

"After all the impossibilities are eliminated, what remains, no matter how incredible, must be the truth."

Lin Xinyi said a famous quote from Sherlock Holmes.

Based on the results of the smoke reaction test and the feedback from the on-site investigation, he could only come to such conclusions;

"That bullet must have hit the bear."

"The bullet head and bullet holes are all in the bear, so we can't find the physical evidence."

"But..."

At this time, there is no need for Maorilan to question it.

Lin Xinyi himself noticed the "loophole" of this only conclusion.

One thing is still hard to explain:

"If a bullet hits a bear, why is there no blood at the scene?"