Chapter 221

Luminol reagent is the reagent often used in film and television works to reveal blood.

In earlier years, luminol still needed to be prepared on-site, but now there are pre-packaged finished products available.

Luminol has a super-strong ability to detect bloodstains.

How strong is it? Bloodstains from several years ago, if not specially treated, can all be revealed.

And even if blood is diluted 1 million times—that is, one drop of blood in a bathtub of water—it can still be easily detected by luminol.

Therefore, wanting to use water to wash away bloodstains is basically futile in front of luminol.

This is also the reason why it is generally not recommended to commit murder at home.

Luminol is a very cheap reagent; 0.1 grams of luminol, mixed with 5 grams of sodium carbonate and 6 milliliters of hydrogen peroxide, can produce a 100-milliliter bottle of luminol solvent.

It is also checked by spraying; spraying a room doesn't take much time either.

Moreover, current DNA technology is also very advanced and highly sensitive; the bloodstains revealed by luminol have just been softened, so a quick swipe with a cotton swab makes it very easy to obtain DNA upon returning.

Furthermore, ordinary toiletries and cleaning supplies are very difficult to use to clean bloodstains to a level where luminol cannot detect them.

To interfere with luminol, one must use oxidizing agents, the most common being bleaching powder and potassium permanganate, but they cannot completely interfere with the luminol reaction either, because the luminescence time of hemoglobin and the interfering substances is different; an experienced crime scene investigator can easily spot the difference.

As for hotel bathrooms, naturally, these things wouldn't be used.

Besides, the cleaning ladies in bathrooms have never been known for being diligent and conscientious.

Jiang Yuan took many photos before the luminol luminescence ended, then said, "Master, you can turn on the lights."

"Alrighty." Wu Jun turned on the lights, his face beaming with smiles.

"So happy?" Jiang Yuan took out his gloves and mask to put them on, then took out a cotton swab and began to operate in a methodical manner.

If there are no surprises, these bloodstains will be the key evidence in this case.

In Bai Bai Yuequn's entire set of lies, there is no room for a single bloodstain from Yuan Yuan Yutang and his boyfriend.

Wu Jun was even more relaxed as he watched Jiang Yuan roll the cotton swab, saying, "Even if he's as cunning as a ghost, he still has to drink this old man's bathwater."

What does "handling two people alone" mean? It means that when arresting people, one person can pin two suspects against a wall and make them unable to move.

Wu Jun chuckled, drew a circle in the air with his hand, and said, "Unless both of their hemorrhoids burst, otherwise, this must be the place where Bai Bai Yuequn cleaned the bloodstains."

Jiang Yuan said "En" and made a slight correction: "Unless a guest's hemorrhoids burst in the bathroom in the last few years, otherwise, this is basically the scene where Bai Bai Yuequn cleaned the bloodstains."

The girls followed behind Wu Wu Junhao and the others, just considering how to strike up a conversation, when they saw the three of them turn and enter a bar named "Blue Star Alliance."

In the city, blood-stained clothes and murder weapons are relatively difficult to dispose of; Jiang Yuan didn't have any ideas for a moment either, only saying, "Let's break Bai Bai Yuequn's alibi first."

"That's right. If this Xu Yi still doesn't talk, scaring him with being an accomplice to a homicide should make him open his mouth." Wu Jun still has quite a bit of experience.

Criminal suspects cannot see a lawyer during the interrogation stage and can only listen to whatever the police say. Therefore, if you don't study hard, after killing someone or accompanying someone to kill, you will be exploited due to the information gap.

"They work out until the end, and then they all like the same sex, right?"

Evening.

Lei Xin had made a meticulous plan and was prepared to interrogate Xu Yi personally.

Lei Xin started out in pre-trial work in his early years. In fact, back when there was a pre-trial department, the police officers who could enter it were all those with solid professional skills. His teeth, stained yellow by his pipe, were also proof of history.

After carefully reading the DNA report again, Lei Xin walked into the interrogation room with high spirits.

Xu Yi was thin and tall; after his hands and feet were locked by the interrogation chair, he looked like a giraffe playing at being tied up, with only his head stretched out particularly long.

"Do you know what we want to ask?" This wasn't Lei Xin's first time interrogating Xu Yi; they had had a brief conversation before, and this time he sat opposite him with a smile on his face, putting down a thick stack of documents.

That pile of documents looked like so much evidence and testimony, which also attracted Xu Yi to look over involuntarily, guessing in his heart.

After a while, Xu Yi shifted his gaze back and, as if finding his footing, said, "I know, you want me to retract my statement."

"I want to save your life, kid; I don't want to watch you be a scapegoat for others." Lei Xin decided to play a strong hand, first taking out a few photos from the surveillance footage, saying, "These are photos we captured of Bai Bai Yuequn scouting the location."

The image investigation squad found a lot of video, and Lei Xin showed them to him one by one.

Xu Yi looked at them, turned his head, and said, "No need to show them; that's just the movie theater nearest to the bar street. We were just going to watch a movie; how is that scouting?"

"Your explanation has some merit." Lei Xin seized the opportunity to praise Xu Yi, then displayed the footage and time of the surveillance damage in Screening Room No. 2.

Then he released photos of Bai Bai Yuequn entering and leaving the theater at about the same time.

When Xu Yi saw the end, he simply closed his eyes and said, "If you really can't find the murderer, just arrest us directly; why make up so many inexplicable things."

Lei Xin looked at his expression, silently took out his trump card, and said, "I have another DNA report here, collected from the hotel room you stayed in that night. How do you explain this?"

Xu Yi was stunned: "What do you mean?"

"In your hotel room, there are bloodstains from the two victims, and the quantity is not small." Lei Xin said faintly, "It should be the blood Bai Bai Yuequn didn't wash clean at the scene, right?"

Xu Yi hesitated for a moment and said, "You're lying to me."

"Assuming I'm lying to you, if I go to the bathroom of the hotel you stayed in now to look for bloodstains, do you think I can find the bloodstains of the two victims?" Lei Xin held the DNA report in his hand and didn't give it to Xu Yi.

Xu Yi couldn't hold on anymore.

"Do you really want to be like Bai Bai Yuequn and sit in jail for the rest of your life?" Lei Xin began to use a sympathy offensive.

Xu Yi's expression changed slightly, and after a while, he said, "There's still work."

"What?"

"Bai Bai Yuequn promised me, don't talk nonsense, and he'd find me another job later. If both of us get a criminal record, it won't be easy to find work." Xu Yi's voice was very soft.

Lei Xin was overjoyed; as long as he opened his mouth, the rest would be easy to ask.

Lei Xin said, "Then let me ask one more time: during the movie screening that day, was Bai Bai Yuequn with you in Screening Room No. 2 watching the movie, and did he leave in the middle?"

Xu Yi said, "I don't know."

Lei Xin couldn't hold back immediately; if he were allowed to eat someone, he could put Xu Yi in his mouth and grind him fine.

"I really don't know." Xu Yi said, "When I entered the screening room that day, I felt a bit tired, so I fell asleep. When Bai Bai Yuequn left, or if he left at all, I don't know."

This sentence cannot convict Bai Bai Yuequn, but it is enough to dismantle Bai Bai Yuequn's alibi.

Not only Lei Xin, but everyone watching the surveillance couldn't help but be happy.

Lei Xin pressed on: "Then on the way from the theater to the hotel, did you notice Bai Bai Yuequn discarding anything?"

Xu Yi said, "No."

"What about the smell? Didn't you smell anything?"

"I was wearing a mask at the time. An N95 one; anyway, I didn't smell anything."