The old policeman exhaled a cloud of smoke and broke the silence. "Even if you really are a cop, we still have to detain you for twenty-four hours, and you can’t leave Hongcheng after that. After all, you showed up at a crime scene while off-duty, and you made contact with the victim."
"Sir, I know the rules, but a twenty-four-hour detention is usually only enforced when there’s no clear evidence to rule out criminal suspicion."
"We will verify everything you just said. But even if your family and the hospital staff can corroborate your story, that doesn’t clear your name.
"Remember, you were caught near the crime scene covered in blood. Most importantly, no one can prove your account of what happened there.
"Without witnesses, it’s just your word," the old policeman said sternly, his expression and tone returning to their previous severity.
"There are no witnesses, but what if there’s physical evidence?"
"What?" Zhou Yi’s words caught the old policeman off guard.
Right then, a knock came at the interrogation room door.
"Captain Wu, it’s Xu from the forensics department."
A young woman’s voice rang out from the hallway.
Hearing this somewhat familiar voice, Zhou Yi’s heart instantly skipped a beat.
He wondered, "Could it be..."
The old policeman stood up and opened the door. The warm yellow light from the corridor spilled over the clean white lab coat of the young woman standing in the doorway.
Zhou Yi never expected to run into her under such circumstances.
Xu Nian, the youngest forensic doctor at the City Bureau—and his ex-girlfriend.
Xu Nian reached up to tuck a stray strand of hair behind her ear and handed over a file.
"Captain Wu, this is the preliminary autopsy report. Please take a look."
Hearing how Xu Nian addressed him, Zhou Yi finally realized who this shrewd old policeman was.
Wu Yongcheng, the vice-captain of the Criminal Investigation Detachment at the Hongcheng City Public Security Bureau.
Back when he was just a rookie cop, he had heard of this man’s reputation. To him at the time, Wu Yongcheng was an untouchable big shot out of his reach. Later, by the time he joined the City Bureau’s Criminal Investigation Detachment, Wu Yongcheng had already been transferred to another city.
Therefore, before his rebirth, the two of them had never crossed paths.
However, Zhou Yi had seen Wu Yongcheng’s name many times in the files of the 316 Case, as this unsolved mystery was originally under his jurisdiction.
Wu Yongcheng thanked her, took the report Xu Nian handed over, and immediately opened it to read.
Xu Nian casually glanced into the interrogation room, her eyes perfectly meeting Zhou Yi’s. She hadn’t expected the suspect inside to be staring right back at her and couldn’t help but find it a bit odd.
A sudden idea struck Zhou Yi. "Captain Wu, that autopsy report is the physical evidence that proves I’m not the killer!" he called out.
This immediately drew the attention of the other two.
Wu Yongcheng shot him a cold, stern backward glance. "Where? I don’t see it."
"How about you let me see the report, and I’ll explain it to you?"
Zhou Yi had certainly read this report before—albeit in a cramped archives room more than twenty years later. But right now, he couldn’t divulge any information pertaining to the report; otherwise, he wouldn’t be able to explain how he knew it.
Therefore, he needed the other party to volunteer the information first.
"Are you kidding me? You think I’d hand case files over to a suspect?"
"That’s fine. I just need to ask four questions to prove my innocence."
Zhou Yi spoke with such absolute certainty that Xu Nian, who had been about to leave, stopped in her tracks and stared at him curiously. She wanted to see how he intended to use the autopsy report she had just drafted to clear his name.
Before Wu Yongcheng could agree, Zhou Yi fired off his first question.
"What was the cause of death?"
Wu Yongcheng hesitated for a moment before answering, "Knife wounds." He, too, wanted to see what kind of trick this kid had up his sleeve.
"How many?"
"Six."
"Which one was the fatal blow?"
Both Wu Yongcheng and Xu Nian felt their hearts skip a beat. The line of questioning was far too professional.
Xu Nian looked at Wu Yongcheng. Seeing him give a subtle nod, she finally spoke.
"The stab to the left carotid artery. The wound is 6.4 centimeters long and 2.7 centimeters deep, inflicted at a 45-degree angle."
Zhou Yi nodded but didn’t say anything else.
Wu Yongcheng waited for a moment. Seeing him fall silent, he immediately asked, "What about the fourth question?"
"There’s no need. This forensic doctor just answered my fourth question alongside the third."
"So where is this proof of your innocence?" Wu Yongcheng asked with a frown.
"The pressure in the human carotid artery is extremely high. When ruptured by trauma, the blood sprays out rapidly."
Xu Nian nodded. A ruptured carotid artery could cause blood to spurt over a meter away.
"Furthermore, the angle of the stab wound perfectly dictates the relative positions of the victim and the killer at the moment it was inflicted." Zhou Yi pointed at himself. "As for the blood on me—other than what got on my hands when I tried to bandage the victim’s wound and stop the bleeding—the rest of the blood on my body came from my own injuries during my struggle with the killer. You just need to take a sample and run a lab test to know if I’m telling the truth or not.
"Given the process required to inflict that kind of wound, it would be impossible for the killer to walk away without a single drop of the victim’s blood on them.
"That is the best proof of my innocence!"
Those few sentences greatly shocked Wu Yongcheng. This kid’s train of thought was exceptionally clear and precise. This angle of analysis wasn’t something an ordinary person could just casually come up with.
"Ahem. Xu, can I have a word outside?"
Wu Yongcheng stepped out of the interrogation room and shut the door behind him.
Out in the hallway, Wu Yongcheng asked, "Xu, do you think his reasoning holds up?"
Xu Nian nodded. "He’s right. His logic basically aligns with the facts."
"Then is there any possibility that the killer slit the victim’s carotid artery without getting a single drop of blood on them?"
"Yes." Xu Nian’s answer made Wu Yongcheng’s eyes light up. But she immediately followed up with, "If the victim had completely lost the ability to resist, and the killer had taken protective measures, then they could have avoided getting blood on themselves."
Wu Yongcheng was momentarily speechless, figuring that was as good as saying nothing at all.
Just then, a young policeman came rushing over, clutching a piece of fax paper.
"Boss, the victim’s identity has been confirmed!
"Also, we’ve identified the guy inside!"