"What a nasty case. The neighbor was transported to the hospital; he breathed some of this stuff in."

"Take a look at this receipt. It was in the trash can."

"I see: Suicide by gas poisoning. We can close this case."

"Just like that? No proper investigation? You're not this negligent usually, Megure. They are overworking you."

"Oh? You have another idea, Kudō?"

"I just might. Look at the dust: furniture was moved. Let's check her calls."

October 25th, 2002: Tōdai General Library

Expert opinions regarding the microscopic comparison of human hairs have been accepted routinely in courts for decades. However, with the advent of mitochondrial DNA (mtDNA) sequencing, an assessment can be made of the association by microscopic hair comparisons in casework between a questioned hair and refere…

"Yo, Earth to Kudō!" Heiji called, a playful grin on his face.

He had found Shinichi buried in his documents, sitting at the corner of a table hidden deep within the social sciences section of the Tōdai General Library. He was surrounded by a mess of haphazardly piled up criminology books, homework folders and science magazines.

Heiji had stood behind him for five minutes with an amused expression, wondering when his friend would notice his presence. Eventually, he lost patience and hit the back of his head with the newspaper he had rolled in his hand. He didn't hold back. Two other students frowned at him, unhappy with the quite loud interruption of their thoughts. They kept quiet and returned to their writing after throwing a strong glare at him. Heiji remained unapologetic. Shinichi rubbed his head and turned an unimpressed gaze at him.

"Would you stop jumping me like this?" he whispered, mindful of his fellow students.

It had been a pain, but after four years spent in hiding, gathering evidence and building his network, he was finally free. Meanwhile, his personal life and studies had stayed suspended in time as the rest of the world moved on. He couldn't really use classified field experience with the FBI as a replacement for an actual diploma. Hence, he took a year to catch-up on high school and pass the government proficiency exam with flying colors. He applied for every university with a criminology program and managed to get himself a spot in the University of Tokyo, or Tōdai for short. It was an achievement, especially considering his bad school records due to years of unjustified absence. He could never retrieve the time he had lost and would always lag behind his age group. He'd missed everything that normal high school life entailed. He, who was already out of step with his peers to begin with. But he was finally making progress with his life.

Heiji had been enrolled at Tōdai since the start of his master's degree earlier this year. There was a teacher whose work he admired here, and if it got him closer to his best friend then it was even better. Shinichi believed the teacher was just an excuse. He recognized he had been in low spirits since his life calmed down and he had the time to fully process the traumatizing ordeal he was forced into for what felt like a lifetime. Surprisingly, he fared much better when he was still in the middle of it than now that it was all over. He had expected Gin's arrest to bring him peace and closure, but his paranoia only worsened, and he was occasionally blindsided by panic attacks. Haibara was openly worried about him and hurried him to contact a shrink. Shinichi dismissed her harshly. That was probably when she called Heiji and he decided to move to Tokyo.

At this thought Shinichi's mood darkened. It was unfair of him but he was bitter. Shinichi was always eccentric, but he used to be social and popular back in high school. He lost it all. Heiji flourished in university: he was smart, approachable, friendly, funny, easy-going, well connected. At his side, Shinichi was seen as a curiosity. An ex-child prodigy, with an austere personality, who used to make the news every other day until he abruptly disappeared from public view. Most people assumed he'd cracked under the pressure, and sent pitying looks his way. Heiji regularly tried to drag Shinichi to parties. He never came. Crowds were overwhelming, to the point that they made him sick. His eyes would scan the whole area, looking for suspicious movement. He'd analyze every interaction, every voice, every piece of clothing, every smell, on constant high alert, waiting for something to go wrong. Heiji would drag him to coffee shops and tell him everything about his wonderful campus life, hoping to brighten his mood, not realizing his friend was seething with jealousy and inadequacy.

Shinichi had lost most of his relationships to Conan. He'd had to build a life and friendships from scratch, and when Conan was no more, he lost everything again. Shinichi was left awkward and unable to connect normally with other people. His friends were worrying over his health and coddling him like he was helpless. Shinichi spent years living as an elementary student pampered by Ran. He didn't want to be treated like a kid anymore! On top of that, he was stuck in second year of bachelor's degree, with classmates who felt alien, and basic course material taught by faculty members who openly complained about their students. Meanwhile, Heiji got to listen to the advanced lectures and had the respect and consideration given to students at graduate level.

If I hear one more teacher complain about the declining level of undergraduate students I might just walk out of the lecture hall, he thought irritably.

It's not like he'd miss anything of note. The important parts were all referenced from books he'd bought at the beginning of the year. He could skip lessons and still get the best grades. Maybe that was why Heiji had come. He knew Shinichi, if left on his own, would live like a hermit for the rest of his student life and wither away.

"How long were ya holed up in this place?" He asked. "It's past 9PM, man. We're not in the exam period. Ya need to get a life."

He emphasized every word of that last sentence with a hit on the table. The other students now looked positively furious. Their scribblings were turning aggressive.

"And why exactly are you here?"

"I was looking for ya, of course! Like the good friend I am. When was the last time ya ate?"

The newspaper caught Shinichi's eye. He raised an eyebrow, intrigued.

"What's this headline?"

"Oh? Didn't read the paper today? Take a look."

Forensic mistake led to wrongful conviction! Sasaki Haruki free after 10 years in prison!

Shinichi hummed. "This isn't a good look for the police."

"It happens. Forensic technicians are human too."

"It's quite the mistake. His fingerprints matched those on the weapon, but DNA exonerated him."

"Guess the fingerprints on the weapon weren't that clear. Someone redid that analysis and didn't find a match."

"This should never happen." Shinichi's voice cut like a razor blade. "We can't base our deductions on faulty data."

"I mean, sure. I agree. But what can ya do? Sucks to be this dude, though. At least he's free now."

"Hey! Would you two shut up or get out?!"

They turned around. The two other students were now scowling at them. One of them was tapping his pen on his notebook as the other crossed his arms. Heiji, embarrassed, put a hand behind his head and made a sheepish smile.

"Let's get outta here. I'm buying ya dinner."

The headline was forgotten for the evening.

"He certainly had motives. And an opportunity."

"His fingerprints were on the receipt."

"No good. He can say he just found it and threw it away. We'll check with the shop."

Shinichi thought about it sometimes, in passing. At one point during Conan's life, he stopped watching crime-related news. It wasn't just that it was an inappropriate pastime for his apparent age. He already saw far too much crime in his everyday life. He didn't want to spend his leisure time keeping track of every sensationalist headline about a murderer and their sobstory of feeling wronged by the world, of being cheated on by their lover, and so on.

He saw so many cases they all started to bleed into each other. He gradually became apathetic towards them. How could he not? But he still took immense pride in the quality of his work. That headline worried him.

What if I missed something? Was the evidence I was given always correct? Did it ever put me on the wrong track? And was I really paying attention during all my cases? I was almost submerged in them at one point.

The more he thought about it, the more restless he became. If evidence could be wrong, then what of the deductions that came from them? Could they still hold up? Should they be thrown out like the fruits of a poisonous tree?

Of course they should! It's not a question! One detail changes the entire scenario.

Shinichi sometimes came up with a good theory before he found the decisive evidence. However, oftentimes he needed that one piece of evidence to get his stroke of genius. On occasions, Shinichi had used shaky evidence to trap criminals into a confession. There even were cases where he had to obtain evidence illegally.

But illegal doesn't mean wrong.

Does it? In western law there was a doctrine for evidence retrieval. Any evidence obtained from a tainted source must be removed and the conclusion drawn from them discarded.

And that's a stupid logic that let many monsters run free.

But could you blame the court for mistrusting an unlawful source? If it was obtained dubiously, why should the evidence be genuine? Shinichi, who had the entire context of his cases, knew that he and the police officers he worked with were honest people acting in good faith. But why should an outsider believe them?

What kind of good citizen doesn't trust the police?!

This was a stupid thought and Shinichi knew it. Lately the Japanese police force had been hit with scandal after scandal. People didn't trust the police as blindly as they used to.

And even before, it wasn't like Shinichi really trusted them. If he had then Conan wouldn't have been a secret to every officer he knew. Conan was still a secret, even from Megure and Takagi.

That's not the same.

Yes it was. Because a single mistake would have cost him his life. That's why he didn't trust anyone but himself and a select few he had no choice but to tell.

Looking at his involvement from an outside perspective: A certified technician could make a mistake. So could an officer. Shinichi wasn't even licensed as a private detective when he started doing this job. He only got it at 21. Legally, he hadn't had the right to be on crime scenes for most of his career, and his involvement, although mediatized, was never officialized. He was accepted by Megure because of his friendship with his father. Something could be said about nepotism. Someone like him, who wasn't even honest with the police, should stay far away from the investigation process. That's what he would think if he were a judge, or that one asshole of an "investigative journalist" who used to write scathing pieces about him.

None of these issues should concern me. I keep a low profile these days. My involvement in cases isn't mediatized anymore. I know I'm not corrupt. The police oversee my investigations. And the criminals I caught all confessed in the end. Nobody can question how we got there. I can focus on the truth and leave politics out of this! Nothing ever went wrong!

How awfully convenient for him.

"The date is January 7th. This is the end of our evening news program. Today we are interviewing Mitsurugi Shin-san for the release of his book: The Defense's Plea: Argue Your Case and Win the Trial. Mitsurugi-san is one of the most controversial and successful lawyers of our times and is known for pulling spectacular non-guilty verdicts out of desperate cases! Please tell us, what is your secret to win in court?"

"There is no secret. Integrity! This is the Gospel. We have to remember lawyers are not here to lie on behalf of a client. We must serve their interest with the evidence available to us and to the court. We must always believe in the sincerity of our client. The contrary will make our job terribly difficult, and the client will always look worse in front of the judge. This is why a lawyer should never let his client lie to him or to the court. This is the most critical requirement for a good defense."

"This is not the idea most people have of defense lawyers! One would think lying would get suspects out of accusations!"

"Lawyers don't exist to get criminals out of a sentence but to prevent the justice system from making mistakes. We also help repentant people to get lighter sentences so they may be reintegrated as productive members of society and move on with their lives. Justice is not meant to punish and instill fear, but to heal and protect society. The victims, of course, but it also includes people who commited crimes and felony."

"These are very strong words! You talked about the mistakes of the justice system. Do you have examples in mind?"

"Oh! I have many! You must always pay attention to the details of a case. You see, policemen are not properly trained in forensic sciences. They will often jump to conclusions and decide on a scenario even before expert opinion! Prosecutors are overworked and have expectations of a perfect record on them. They often throw away cases that they believe are flawed, in fear that they will not be able to sentence a suspect and that it will tarnish their records. Sometimes, the police or the prosecutor believes very strongly in the guilt of a suspect, but the evidence is still weak."

"So they would not put him on trial?"

"They would. For this, they will make a piece of evidence look stronger than it really is. During trial, but also during interrogations. They use these flimsy clues to put pressure on suspects and force them to confess and plead guilty."

"But if they confess, isn't it proof of guilt?"

"Not necessarily! I once had a case where the client was proved to be on the crime scene at the time of the murder through their cell phone's records. As you probably heard, the police routinely ask phone companies to tell them which cell tower relayed the suspect's phone calls or text messages."

"Yes! You see it a lot in detective shows."

"I once had a talk with an engineer from a phone company. According to him these records shouldn't even be used in court! I'm not a specialist but I will try to explain what he said: During your call, a program will analyze a list of different factors and distribute it to the nearest tower… depending on its calculations! If the nearest tower can't take your call, the program will simply relay it to the next tower, and the next, and the next, until it finds one that will actually connect. Cell phone records are a way for phone companies to manage their data, not for the police to find a phone's location!"

"But the police can find missing people with their phones!"

"It is because when they are actively tracking a number, they will use three different towers to pinpoint its location! An emergency call to 110 will also automatically track your phone. However, a normal call will not leave this kind of information behind. So unless your phone has a GPS, it is impossible to prove you were at a crime scene!"

"They don't tell you this on TV! Are judges and lawyers aware?"

"Sadly, they aren't. Many judges and lawyers have little knowledge of forensic science or technology. My client's previous lawyer advised them to plead guilty to lighten their sentence. There were other elements, mind you; the investigation revealed my client had bad blood with the victim. However, they were innocent."

"This is terrifying! Do you have any advice for people in trouble with the police?"

"Ask if you are under arrest. If you are not, don't follow them. If you are under arrest, don't try to talk your way out. Stay silent. Don't sign anything. Take a competent lawyer."

"Thank you very much Mitsurugi-bengoshi-san. This was the end of our evening show."

*ring* *ring* *click!*

Heiji checked the number and joyfully talked into the handset. "Hey Kudō! What's up? It's unusual for you to call me yourself."

"...Why do you make me sound like a bad friend?" Shinichi asked in his weird mix of pouty and bored.

"Ya are a bad friend, haha!"

"..."

"Just kidding man! I know it's just how ya are. Always up in your little world, letting time pass, forgetting even your own birthday."

"I'm hanging up," he snapped. He seemed in a bad mood.

Heiji panicked. "Nonono wait! I'll shut up! Speak to me, please!"

"No, it was stupid." he said, despondent.

"I'm sure it's not!" Heiji realized he actually hurt his friend's feelings. Perhaps at one of the rare moments when he was actively seeking his help. "Ya never worry over small things. If ya call, it must be serious."

"..."

Sheeesh! Ya fucked up, Heiji! Keep him on the line! He admonished himself. "Come on! Don't be like that, ya know I didn't mean it!" No, no, bad idea! Switch topic! "Not ready to talk? I'll talk then! So, remember that weirdo I told ya about?" Good, good, Kudō loves gossip. "The one who follows the Public and Private Policing course? Well it turns out his girlfr-"

"Do I have any legitimacy as a detective?"

"-iend was… Repeat that?"

"Nevermind," he sounded like he was about to really hang up.

"WHAT!? Of course ya do! Ya're the best out of any of us! Shit! Don't count on me to say it again. What the heck got ya thinking like this Kudō?" This really wasn't like him.

"Maybe none of us are legitimate."

Heiji frowned. "What d'ya mean?" He was definitely going to get a headache out of this conversation.

"You, me, Sera, Hakuba… Maybe we just butt in where we are not needed or wanted. Maybe we interfere with the proper course of investigations. Maybe we should leave them to the police and not be involved at all."

Heiji recoiled. He'd had years of arguments with his father on the topic. Hearing almost the same words coming from Shinichi, who inspired him on this path, felt like a slap. "...Ok, this is very serious. What got your panties in a bunch like this?"

Shinichi hesitated. "I… was just thinking. Did you read that FBI study in the Journal of Forensic Sciences? The September volume."

"The one on hair comparisons? It had pretty interesting data. Nice to have an actual error rate but it's not like it came out of nowhere." Heiji didn't see the connection.

"Yes… However, before this, most people in the field just assumed those results were solid without proof."

"Well, they are just one argument out of many others to pinpoint a culprit. It's not like investigators only look at hair fibers and say: this guy is guilty! Arrest him!"

"But it would be case-turning evidence."

"Yes. What's your point?"

"What if… The investigator was biased by this clue? What if it gave him tunnel vision?" he tried.

"I'm starting to see where ya're going with this. Let me stop ya right now; ya don't need to worry too much about it."

"H-how can you say that?!"

"How can I say it? Kudō, what's our job?"

"We seek the truth!"

"Yes. We do this to catch criminals and protect people. For every crime scene, we evaluate each scenario, we find the most likely suspect, and we put that guy on trial so he can't hurt anyone else. That's all. The rest ain't our problem." This entire conversation was starting to make him feel uneasy. Hearing this kind of candid doubt come from someone he saw as a pillar of justice was disconcerting.

"Of course it's our problem! We're looking for the truth!"

"Yes. And nothing we find in these investigations is wrong. There may be a few flimsier clues where human judgment is needed but I think we already do well enough at preventing bias. I know exactly how ya work. If a guy is put on trial after one of your deductions I'm damn sure he's guilty!"

"Did you listen to Mitsurugi-san's interview yesterday?"

"That dude? He's a defense lawyer! A famous one! Of course he's gonna overstate miscarriage of justice on the news! That's his schtick! Ya can't watch an interview of a guy like this and take his words like a personal attack, Kudō. I thought ya were the rational one."

"I am being rational! We are celebrities. If we ever made a mistake back then, before we had our license, the public will turn on the police for even letting us on crime scenes. It could get all of our cases retried! It could even get us prosecuted! Get officers prosecuted!"

"What 'bout this is rational?! Nobody's putting ya on trial except yarself! Ya think removing ourselves from investigations is gonna make things any better? Especially now that we're licensed? That's dumb! Ya know ya always did your best on every case ya worked on. Ya always stay as informed as possible on the latest methods. And sure, sometimes these methods ain't as reliable as we believed, but so what? This is expert business; let them settle it between themselves. We ain't scientists! We ain't lawyers! The only thing we can do 'bout this is keep learning and move on. Do better next time."

"There is no next time for the people already arrested. How can we really be sure we had the right person? There is always a small chance of making a mistake…"

"Of course! But if ya start questioning everything under the sun how are ya gonna solve any case, Kudō?"

"You don't get it."

"I don't get it?!" Heiji all but shouted. "Of course I get it! I was a teen detective too!"

"YOU DON'T GET IT!" he shrieked. Heiji almost dropped his phone in surprise. "You solved what, a few sporadic cases in between days of your normal teenage life?! I saw cases every. Damn. Fucking. Day. For years. Since I was a kid, Hattori. I can't even tell them apart anymore! At some point, I think I stopped caring."

He let out a small sob. The sound chilled Heiji to the bone.

"Even now I get called almost every week. It used to be everyday. I put almost a thousand people behind bars, Hattori! I looked at the numbers! Mathematically, I could have put dozens of innocents in prison! At the very least!" Shinichi's tirade was turning hysterical. It seemed he couldn't stop the flood of doubt he never dared to vocalize until now.

"Kudō, you can't calcu-"

"What if they are on death row, Hattori? What if they are already dead? How can I live with this?"

The magnitude of his words, the anguish in his voice, punched the air out of Heiji's lungs. He swallowed a gasp. "Wow, Kudō… Wow."

It could have been seconds, or minutes, but for a moment he could only hear the sound of heavy breathing, sometimes broken by a hiccup or a sob, echoing on the line. Nobody spoke. Heiji let him recover. He took a moment to gather his thoughts. He had to tread very carefully with this.

He spoke softly. "I think I get it now. But Kudō, my opinion didn't change."

"..."

"Ya can't let these things eat at ya. Because I mean it. Ya're one of the most inspiring, brilliant, rigorous, hard on yourself people I've ever met. This is because ya know life is precious and sacred."

"B-but I-" he crackled.

"Ya're tired. I got it. But despite this, I know ya never made an accusation lightly. Ya always take everything into account. Evidence, motive, context, witness statement. Ya're always so careful with everything and ya never get anyone arrested if there is a single doubt, right?"

"...I do my best," he whispered.

"Of course ya do. That's how ya are. 'Mathematically' my ass! That is an average. Kudō Shinichi ain't an average detective! So don't just give up because maybe you made a few mistakes, Kudō. Think of all the good you did. Think of how many murderers would be free without you. Of how many victims and family members wouldn't be appeased."

"...uhn," he acquiesced.

Heiji continued. "If ya stop detective work because of this… it would be like running away. And I know ya'll feel even worse. All of us… We all make mistakes. That's an inevitable part of human life. We just have to live with them. Of course it's gonna be hard but ya're not alone, got it?"

"M-maybe you're right," he said, voice raspy from his earlier outburst.

"Of course I am!" Heiji took a brighter tone. "Take a break from cases, ok? Just let others do the job for a few weeks. If ya need anything, ya can always count on me."

Shinichi gave a small, wet chuckle of acknowledgement. "Thank you, Hattori."

"Any time."

"The cashier testified: our suspect was the buyer. Case closed, sirs !"