Chapter 178: Verifying the Hypothesis

The "involuntary" words spoken by Akikawa Kyousuke instantly revived Conan and Sera Masumi, who had been stuck in a dead end due to Koizumi Kunio's refusal to cooperate.

In this case, what baffled the two detectives the most was why Koizumi Kunio wanted to cover up the fact that the deceased, Ryo Kawasaki, had been using a computer.

After all, Kosenan was a hot spring hotel for vacations.

Everyone's initial assumption was that Ryo Kawasaki had come there to relax.

However, when they learned that this hot spring hotel, in addition to its healing waters, was also highly popular among programmers, the situation took on a completely different context.

---

"Mr. Kawasaki wasn't here for a vacation at all."

"As a senior programmer at a major IT company, the reason he stayed at Kosenan for so many days without leaving must have been that he was working overtime developing software."

"The description from the staff responsible for delivering his meals also confirms that Ryo Kawasaki couldn't rest properly after arriving at Kosenan."

"There must be some reason tied to Mr. Kawasaki's death, and Mr. Koizumi didn't want the software Mr. Kawasaki was developing to be exposed. That's why he dismembered Mr. Kawasaki's body—even though he was still using a computer."

"After all, the average person wouldn't know the connection between this place and programmers."

"So as long as the police didn't know that Mr. Kawasaki was using a computer when he died, they wouldn't investigate the software he developed."

---

After piecing this together, Sera Masumi turned to Officer Okamura, who stood nearby.

"Officer Okamura, can you investigate Mr. Koizumi's previous occupation?"

"I think, given that this hotel is so popular among programmers, there must be more to it than just the hot springs' restorative effects on the body and mind."

"—There must be a specific reason why a group of programmers would gather here."

---

Officer Okamura nodded and was about to give orders when Kunio Koizumi spoke slowly:

"No need to check. I was a programmer before I started running this hot spring hotel."

This time, Koizumi Kunio's tone was no longer as firm as before; instead, it was filled with despair.

---

Originally, he had believed that after dismembering Ryo Kawasaki, no matter what the police did, they wouldn't be able to link Ryo Kawasaki's death to the computer.

Unexpectedly, the high school detective quickly deduced that Koizumi had dismembered the body to conceal the posture Kawasaki Ryo had maintained at the time of his death.

---

Kunio Koizumi wanted to stop the police investigation by confessing to the crime himself.

Unfortunately for him, Akikawa Kyousuke had unexpectedly appeared out of nowhere and casually provided the most crucial piece of information to the detectives.

When Kunio Koizumi heard Sera Masumi's reasoning, he knew he couldn't hide it anymore.

Because once the National Police Agency made Sera Masumi's deduction public, it would all be over.

---

"Then, could you tell us everything that happened yesterday?"

Officer Okamura added.

Kunio Koizumi nodded in despair and said, "Yesterday, after I finished giving my statement at the police station, I returned to Kosenan and found that Kawasaki had been killed."

---

"You didn't kill Mr. Kawasaki?!"

The officers present showed great surprise upon hearing Kunio Koizumi's words.

In their minds, once the Forensic Division had confirmed there was a significant amount of blood in Koizumi's bathroom, they had already identified him as the murderer.

---

"So who killed him? And how did he die?"

Officer Okamura pressed for more information.

"...I'm not sure."

After hesitating for a moment, Kunio Koizumi gave an ambiguous answer.

"But Kawasaki probably died from a stab wound to the neck."

---

"A stab wound to the neck? But we didn't see any stab wounds on Mr. Kawasaki's neck."

One detective said in confusion.

"That's because Mr. Koizumi concealed the wound by dismembering the body," Sera Masumi explained.

The officers present showed slight expressions of horror upon hearing this.

Before Sera Masumi's explanation, none of them had considered such a gruesome method.

---

Koizumi Kunio's description once again validated Akikawa Kyousuke's earlier speculation.

From the start, Akikawa Kyousuke had noticed that only the deceased's neck wasn't severed along natural joint lines. He had deduced that the person who dismembered the body might have been trying to use the cuts to hide the fatal wound caused by the real killer.

---

Suppose the dagger had been thrust horizontally into the deceased's neck.

When dismembering the body, if the knife followed the path of the original wound, the fatal injury would be covered by a larger "complete cervical dissection."

This was similar to how Ohga Takao had previously concealed an injection mark with a gunshot wound.

---

However, some officers raised new doubts.

"No matter how severe the neck wound, it wouldn't result in instant death, would it? How could the deceased have maintained the posture of using a computer under those circumstances?"

"If a major blood vessel, like the carotid artery or jugular vein, were punctured, death could occur in extreme cases within one or two minutes," Sera Masumi replied.

"Assuming Mr. Kawasaki was stabbed in a fatal location or lost consciousness immediately upon being stabbed, it's possible he could have maintained the posture of using a computer."

---

As she spoke, Sera Masumi glanced at Akikawa Kyousuke standing by the door.

There was also a scar on his neck.

That scar had been left by Kyouji Toda, who had stabbed Akikawa Kyousuke with the dagger used to kill his mother in a car accident over half a month ago.

Had Akikawa Kyousuke's luck been any worse, he would have died back then.

---

Sera Masumi turned her gaze away from Akikawa Kyousuke and back to Koizumi Kunio.

"So, what exactly was the software you and Mr. Kawasaki were developing? And why would you rather dismember your friend than call the police?"

"Because... if the police find out, my family will be in danger," Kunio Koizumi said, making another shocking statement.

---

Stunned for a moment, Kanagawa Prefecture officer Okamura suddenly snapped, "Were you threatened, Mr. Koizumi? Why wouldn't you trust the police?"

Sera Masumi and Conan exchanged wordless glances after hearing this.

Just minutes ago, this officer had been ready to arrest Koizumi Kunio as a criminal and take him to the station. Now, he had the audacity to ask this.

---

Koizumi Kunio turned to look at Officer Okamura and said coldly, "If this detective hadn't been here, would you have been able to uncover the truth?"

Officer Okamura's face flushed red. After a moment's hesitation, he awkwardly replied, "Of course... of course! At most, it would take more time. As long as we thoroughly review the surveillance footage, we'd definitely catch the truth, Mr. Koizumi."

"But you'd never know Kawasaki was using a computer when he died," Kunio Koizumi sighed.

---

"In summary, that's what happened. It's true that I dismembered the body. I also destroyed the fatal wound on Kawasaki's neck. There's no evidence left."

"Just think of me as the one who killed Kawasaki and take me to the station."

"When I face the prosecutor and the judge, I'll also say I killed him, so they won't continue pursuing the case."

"If the truth is discovered, my family definitely won't survive."

(End of Chapter)

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