Chapter 168 Looking for traces
When Mao Lilan took the lead alone and identified the murderer under the spotlight, she felt full of accomplishment.
It was different from the training opportunity Lin Xinyi specially provided during the last murder case in the art museum.
This "C-position appearance" was earned through her real contributions and her own abilities.
Compared to the Ochiai curator of the museum, the murderer’s murderous plot in this case was even more sophisticated:
The murderer fired several shots in the utility room on the fourth floor beforehand, leaving bullet casings and bullet holes to disguise the scene.
During the live broadcast in the evening, he took advantage of the 3-minute program break to rush to the utility room on the 9th floor and shot from upstairs, killing the deceased on the 4th floor who had been lured over by the phone call.
Then he threw the gun from the 9th floor into the window on the 4th floor and returned to the live broadcast site.
In this way, the murderer has a perfect alibi.
To be fair, this murderous plot was clever enough.
Mao Lilan believed that even if her childhood sweetheart who was a famous detective took action in this case, it would probably take a lot of effort to see through the truth.
But this time, within just ten minutes after entering the scene, she cracked the murderer's method with Lin Xinyi's reminder.
"I did it!"
"Now even that reasoning madman can't leave me behind, can he?"
Mao Lilan thought so in her heart.
Of course, she didn't know that the reasoning madman was actually standing in the crowd of onlookers right now——
Just like before, she had become the one who was left out and a complete background.
In short, with a positive and exciting attitude, Mao Lilan unconsciously imitated the great detective Kudo, and vigorously exposed the murderer's tactics under the spotlight.
And Matsuo Takashi's trick was indeed successfully exposed by her.
But
"You want evidence?"
Mao Lilan encountered unexpected trouble:
That guy Matsuo still dared to resist when his tactics were exposed in public. It was obvious that he had made preparations in advance to clean up the traces.
Cell phone call records, gun smoke reactions, and fingerprints on the gun
These traces that Matsuo voluntarily mentioned are also the most effective evidence that can solve this type of shooting case, and I am afraid they have all been cleared away.
So what other evidence can she use to prove the murderer's guilt?
Mao Lilan pursed her lips tightly and looked a little shaken:
She suddenly missed the murderers she met when she and Kudo Shinichi were together.
Either those guys don't know how to clean up the traces, or their psychological quality is extremely fragile.
As soon as the murder method is revealed by the detective, he will kneel on the ground and cry and confess.
But now, it's her turn to be a "famous detective" and she has clearly solved the murder plot.
Instead of surrendering, the murderer dared to challenge her.
"what to do."
Miss Maori couldn't help but feel a little confused.
The curious and expectant eyes of the onlookers and the crazy and provocative eyes of Matsuo Takashi inevitably made her a little impatient.
"Miss Mori, there is nothing to worry about."
Lin Xinyi's steady and powerful voice quietly sounded in his ears:
"We are forensics, not detectives."
"Cracking the ruse is just the beginning of our work. Using scientific eyes to find evidence and using strong evidence to restore the truth is our real way of fighting."
"Well" Mao Lilan was stunned for a moment, and then realized:
Indeed, she unknowingly put herself into the role of detective, thinking of using that gorgeous and brilliant way to reveal the murderer's true colors in front of others.
But real criminal investigation work is never that simple.
Not all murderers are balloons that will reveal themselves at the slightest prick.
"I understand." Her eyes gradually became firm: "Mr. Matsuo!"
"What, what?" Matsuo Takashi was so frightened that he trembled violently.
He investigated Mao Lilan for an interview and knew that she was the Kanto region women's karate champion.
It was also known that she had sent several critically ill patients to the ICU ward of Mihua Hospital in a "justifiable defense" manner.
He also knew that her mother was the famous barrister Concubine Miles. After being beaten, a certain prisoner wanted to ask a lawyer to sue Mao Lilan for excessive defense. As a result, the lawyer found out that the defendant was the daughter of the "Invincible Myth" barrister Concubine. Even the lawsuit No one dared to answer it.
This is simply the little bully of Rice Krispies Tekken, so domineering that it’s scary.
Therefore, when he suddenly heard such a loud shout, Matsuo Takashi thought that this violent girl was so angry that he was trying to squeeze her out, and she was unable to fight with him with force.
But Mao Lilan didn't take action.
She just looked at Matsuo firmly and said in a solemn tone:
"Dr. Edmund Lockard said that there is no such thing as a perfect crime, only undiscovered clues."
"Please wait patiently"
"We will definitely find the evidence you want."
At 10:40, after issuing a challenge to Matsuo Takashi in front of the live broadcast camera, Lin Shinichi and the others hurried back to the 9th floor.
At this time, large teams from the First Search Section and the Forensic Section had arrived at the scene from the Metropolitan Police Building not far from the TV station.
Lin Xinyi handed Matsuo to the Search Section 1 for temporary custody.
At the same time, he asked the forensics department to conduct a smoke test on Matsuo Takashi, and was responsible for investigating whether there were fingerprints and skin flakes on the pistol.
Lin Xinyi himself, together with Mao Lilan and Asai Narumi, were investigating the utility room on the 9th floor.
The utility room on the 9th floor is directly above the utility room on the 4th floor where the murder occurred.
Not surprisingly, this was the crime scene where Matsuo Takashi shot Suwa Michihiko.
They came here to investigate in order to find evidence that Matsuo committed murder.
And Miss Mao Lilan, who had just declared war on the suspect Matsuo sternly under the live broadcast camera, came to the scene at this time, but couldn't help showing her inner uneasiness:
"Mr. Lin Xinyi, where should we start?"
"Yes." Asai Naomi also sighed softly: "If the smoke test really doesn't work, and his fingerprints and skin flakes can't be found on the gun, how can we prove that he fired the gun?"
"Don't worry about these issues yet."
Lin Xinyi, however, is not as eager to find a clear direction as Xiaolan and Chengshi:
"Do a good job of on-site investigation and find all the clues we can find."
"Perhaps in time, the answer will emerge on its own."
"Stop hanging around and start working."
"This utility room is not big. If there is evidence, it should be found soon."
"Yeah" Mao Lilan and Asai Chengmi nodded in unison.
During on-site inspection, the first thing to check is suspicious items that can be found with the naked eye.
And they soon had the results of their work:
"There is a transparent umbrella hidden in this cabinet!"
"There is a hole as thick as an arm in the center of the umbrella."
Asai used his gloved hands to carefully take out the transparent umbrella from the cabinet:
"I see!"
"The murderer must have put on gloves and stretched the pistol out of the hole under the umbrella before shooting."
"In this way, all the shooting residues that are sprayed out when shooting will be blocked by the gloves and umbrella!"
"This is what the killer used to evade the smoke test."
"That's right." Lin Xinyi encouraged him without hesitation, but poured cold water on him mercilessly:
“But it’s no use just knowing the techniques.”
"Look, are there any fingerprints left on the umbrella?"
"Or can we find the gloves he was wearing?"
"This" Asai Narumi was slightly startled.
He immediately took a magnifying glass to carefully observe the umbrella body, and then carefully searched the room:
"No. There are no fingerprints on the umbrella."
"The pair of gloves can't be found in the room. They may have been disposed of by the murderer in some way."
"Then this umbrella cannot be used as evidence."
"It can't even prove that this utility room was the crime scene where the murderer shot and killed."
Lin Xinyi sighed softly:
To prove that Matsuo Takashi is the murderer, we must first prove that the murderer used the shooting technique from the ninth floor to kill.
To prove that the murderer used this method to kill, in addition to the bullet holes that have been found on the ground, it is also necessary to prove that the utility room on the ninth floor was the crime scene where the murderer opened fire.
The utility room on the 9th floor was the scene of the crime, and so far they have only deduced it from the facts of the case.
To prove this, we need to produce solid evidence.
"Let me think."
"The murderer stuck his head out the window and shot downward."
"The shell casing must have been thrown out of the window and onto the road. It cannot be found in this room."
"However, the murderer used an automatic pistol."
"And the smoke jet from the automatic pistol is in the shape of a downward semicircle."
"So, even if the umbrella blocked the shooting smoke and prevented it from being sprayed back towards the murderer, some of the shooting smoke would still be sprayed onto the wall outside the window."
Lin Xinyi quickly thought of a way to prove that the utility room on the 9th floor was the crime scene:
"There must be residue left by shooting on the outer wall of the window in this utility room!"
"As long as we extract the shooting residue on the outer wall of the window and do a gun smoke test, we can prove that this is the crime scene where the murderer fired!"
"Miss Maori, you are responsible for extracting the shooting residue!"
"Yeah." Mao Lilan nodded.
"By the way, do you know which method should be used to extract it?" Lin Xinyi asked specifically.
Not surprisingly, good student Mao Lilan gave the perfect answer:
"The exterior wall of a window is an object with a relatively smooth surface, but also a relatively uneven surface, with large pollution and low smoothness."
"To extract the shooting residue on such objects, the AC paper extraction method should be used."
AC paper is a film made of special fibers with strong adhesion, film strength and permeability. It is suitable for extracting shooting residues from uneven surfaces.
Answering Lin Xinyi's question, Mao Lilan quickly opened the on-site survey box and fumbled to operate it according to the knowledge he had learned.
She first used tweezers to hold a piece of AC paper and soaked it in acetone liquid.
After the AC soaked and softened, Mao Lilan carefully took it out and attached it to the outer wall of the window where there might be shooting residue.
Then, she carefully attached the second piece of AC paper and pressed it gently with her fingers.
The AC paper covering the wall quickly dried. Mao Lilan gently peeled it off the wall and stored it. The shooting residue on the wall was also extracted.
While she was busy extracting the shooting residue from the wall
Lin Xinyi and Asai Narumi were not idle either.
They temporarily turned off the lights in the utility room to create a dark room without light source interference.
Then, he took out a multi-band light source flashlight from the survey box - after Lin Xinyi took charge of the forensics class, the Metropolitan Police Department was finally willing to purchase this practical survey tool.
Lin Xinyi adjusted the light source of the flashlight to a wavelength of about 440nm, and began to work with Asai Narumi to look for traces at the scene that were difficult to find with the naked eye.
Under this wavelength of light, most body fluid stains will be stimulated to emit light natural fluorescence.
"found it"
"There was a stain of dried saliva on the cardboard boxes stacked by the window!"
Lin Xinyi discovered an important clue.
Asai Narumi carefully observed the saliva stains and asked with some worry:
"Mr. Lin, are these saliva stains left by the murderer?"
"Nine times out of ten."
Lin Xinyi pointed to the saliva marks on it and said:
"Look, this series of saliva stains are all distributed in a splatter shape."
"Why is it like a splash? Because when they leave the human body, they have a jet power."
"And that's the motivation."
"Sneeze? Or, cough?"
Asai Narumi quickly reacted:
"By the way, that guy Matsuo just happened to have the flu!"
"He has been coughing and sneezing, and these saliva spots are probably accidentally sprayed out when he committed the crime!"
Thinking of this, Asai Narumi couldn't help but said happily:
"Mr. Lin, isn't that enough?"
"There is DNA in the saliva stains, which can prove that Matsuo has been here."
"There are shooting residues on the outer wall, which can prove that this is the crime scene where the murderer opened fire."
"In this case, doesn't it prove that Matsuo is the murderer?"
"It's not that simple." Lin Xinyi shook his head:
"What if he makes excuses and says that he has been here during the day or in recent days?"
"This" Asai Narumi choked slightly.
"It can prove that Matsuo came to the scene of the crime, but it cannot prove that he was the murderer who shot here."
Lin Xinyi sighed deeply and continued:
"So, what we have to find a way to prove now is"
"At the time when the deceased was shot, Matsuo was at the crime scene."