Xie Xinghe was quickly taken into the interrogation room.
The police officer asked directly, "Your class had a chemistry lab session last Wednesday afternoon in lab number 3, right?"
Xie Xinghe: "Yes."
Police officer: "Didn't the lab class cover organophosphates? Did the chemistry teacher show you a bottle of reagent as a demonstration?"
Xie Xinghe replied calmly, "Yes."
Police officer: "So, you were the one who checked the medicine and put it back in the cabinet?"
Xie Xinghe paused for a moment, then said, "I am the class monitor. It is my duty to check the instruments and reagents after the experiment is completed."
Police officer: "Half a bottle of medicine is missing. Did you take it?"
Xie Xinghe frowned: "No, the bottle was full when I checked it."
The police officers exchanged glances and noticed that Xie Xinghe's expression was calm and he didn't seem to be lying. Moreover, his testimony was indeed without any loopholes, so they let him go back first and called the chemistry teacher in.
Qin Weiwei, currently the prime suspect, walked into the interrogation room with a look of bewilderment on her face.
She sat down and asked, puzzled, "Officer, what do you want to know?"
The police officer said, "Didn't you ask for leave yesterday? But we went back and checked the surveillance footage all day. The footage from the school gate shows that you went back to school around 11:20 and left around 11:40."
Upon hearing this, Xiao Lou paused slightly, then immediately perked up.
Qin Weiwei explained, "I took leave to take my dad to the hospital, but I found that he had forgotten his medical insurance card at school, so I took a taxi back to get it."
Police: "So, during the time Ying Xiaoya jumped to her death, you were actually at school."
Qin Weiwei's expression changed, and she said, "You don't suspect me, do you?!"
The police officer said sternly, "Please answer my questions and cooperate with the investigation."
Qin Weiwei took a deep breath and said, "I was indeed at school during this time. I even called the PE teacher to ask about the students' situation. He said he was organizing the students to play basketball. I didn't know Ying Xiaoya jumped off the building. I took my medical insurance card and left."
Police officer: "Last month, the security guard lost his key. Did you find it and return it to him?"
Qin Wei nodded slightly: "That's right."
Police officer: "So, it's entirely possible that you went and made a copy of the key to the rooftop?"
Qin Weiwei's face was extremely ugly: "What do you mean? Why would I need a key to the rooftop? After I found the key, I was in a hurry to get to class, so I left it in the office and returned it to the security guard after class. Maybe someone took the key in the meantime!"
Police officer: "Did you buy this bottle of organophosphate?"
Qin Weiwei: "Yes, I was teaching my students about organophosphates and inorganic phosphorus, so I bought a bottle to help them recognize this poison and avoid accidental contact. I also taught them first aid for organophosphate poisoning... Wait, why are you suddenly asking this?"
police:"
Organophosphates were found in the deceased's blood, indicating she had been poisoned before falling. Half of the reagents in the chemistry lab had been removed. Xie Xinghe said that when he checked, the lab was still full; the only person who could freely take reagents from the lab was you.
Qin Weiwei's face turned deathly pale: "I didn't take it!"
Police officer: "Ms. Qin Weiwei, you are suspected of murdering Ying Xiaoya. This is an arrest warrant."
Qin Weiwei looked incredulous: "Officer, you've got it wrong! I really didn't take any medicine, nor did I make a copy of the key. I went back to school just to get my dad's medical insurance card. My dad can vouch for me..."
Police: "Please return to the police station for questioning."
Before she could finish speaking, a pair of cold handcuffs were put on her wrists.
The police, armed with an arrest warrant, took Qin Weiwei away as a criminal suspect.
Xiao Lou hurriedly followed the police officer out the door.
Yu Hanjiang pretended to be passing by and went into the restroom. Xiao Lou also entered the restroom wearing an invisibility cloak.
Xiao Lou whispered in Yu Hanjiang's ear, "Qin Weiwei is too suspicious. She found the security guard's key, happened to be back at school at the time of the incident, happened to call the PE teacher, and coincidentally bought organophosphate poison."
At this moment, Xiao Lou's Invisibility Cloak effect had not yet ended, so Yu Hanjiang could only hear him speak, but could not see where he was.
However, Captain Yu remained very calm, speaking to thin air with an unperturbed expression: "So, the police took her back for questioning?"
Just then, Xiao Lou's cloak lost its effect, and he appeared out of thin air beside Yu Hanjiang.
Yu Hanjiang glanced at him and asked, " What does Professor Xiao think?"
Xiao Lou frowned: "I feel something's not right."
Just then, notifications popped up simultaneously in both of their floating chat windows—
[ Red Heart 3 Escape Room Deduction: Is the murderer chemistry teacher Qin Weiwei? Yes/No]
[Note: Failure to deduce correctly will result in failure and being sent to the Nightmare Secret Room for punishment.]
The two looked at each other and pressed "No" at the same time.
They all said in unison, "Qin Weiwei is not the murderer."
Yu Hanjiang looked at Xiao Lou approvingly and asked, "How did you analyze it?"
Xiao Lou gathered his thoughts and said, "First, Teacher Qin has the key to the chemistry lab. If she wanted to take the organophosphate poison, she wouldn't need to pick the lock, but when we checked the lab last night, we found signs that the lock had been pried open. Second, she is a chemistry teacher. If she really wanted to poison Ying Xiaoya, she had many ways to do it. There was no need for her to take the poison from the chemistry lab and leave such a big handle on her."
He paused, then continued, "According to the Forensic Doctor's test results, Ying Xiaoya was poisoned, and the source of the poison was the chocolate Yu Hui gave her. However, the amount of poison that a sandwich chocolate can hold is very limited, and this dose of organophosphates is not fatal. Unless Ying Xiaoya was so hungry that she ate the whole box of chocolates —but there was a lot of chocolate left in Yu Hui's bag, which means that Ying Xiaoya probably only ate one or two pieces."
Upon careful review of Yi Ru's testimony yesterday, it was revealed that during physical education class, the boys were playing ball. When the two returned to the teaching building, Ying Xiaoya said she was very hungry and asked Yi Ru to buy her some food. While Yi Ru was at the convenience store buying potato chips, Ying Xiaoya, perhaps unable to bear the hunger any longer, ate a chocolate chip.
During morning exercises in Chinese class, Yu Hui once slipped a chocolate into Ying Xiaoya's pocket.
Xiao Lou happened to notice this scene at the time— Yu Hui had given her a spherical chocolate about 3cm in diameter, wrapped in gold candy wrapper, and Ying Xiaoya must have eaten this one.
The amount of poison in a chocolate sandwich is very low and will not cause immediate death to the user. However, acute organophosphate poisoning can still cause symptoms such as pupil constriction and muscle tremors. As long as timely rescue is provided, the person will be fine.
After eating chocolate, she went to the rooftop and fell to her death.
Xiao Lou finally confirmed, "Her real cause of death is still a fractured skull and brain hemorrhage caused by the fall. The dosage of chocolate poisoning was not fatal."
After Xiao Lou's professional analysis of the poison dosage, Yu Hanjiang became even more convinced of his deduction.
He whispered, " Yu Hui's chocolate has been tampered with. On the surface, Qin Weiwei has plenty of time to commit the crime, and all suspicion points directly to her... However, the police overlooked a crucial point."
Yu Hanjiang looked at Xiao Lou and asked him a question: "If you wanted to kill someone, would you poison them and then go through the trouble of pushing them off the building?"
Xiao Lou's eyes suddenly lit up.
—That's right, poisoning and falling from a building are both ways to kill someone, there's no need to use them twice!
This is simply "adding legs to a snake".
If the murderer wanted to poison Ying Xiaoya, firstly, they shouldn't have used a food like "sandwich chocolate," which contains a very small amount of poison, and put it in Yu Hui's chocolate... What if Yu Hui ate it? Wouldn't that have been poisoning the wrong person? A better method would have been to secretly and quietly add a large amount of poison directly to Ying Xiaoya's food, ensuring her death.
If the murderer intended to push Ying Xiaoya off the roof to her death and then copy her suicide note to create the illusion of her suicide, there would be no need to go to the trouble of poisoning her, which would instead allow the police to detect the poison on her body.
Xiao Lou stroked his chin and pondered for a moment before saying, "Could it be that two people committed the crime? But their statements contradicted each other, leaving a loophole?"
Yu Hanjiang's gaze deepened: "That's right."
This is something Yu Hanjiang finally figured out after carefully organizing all the clues from the past two days and the testimonies of all the suspects.
The Ying Xiaoya case can actually be broken down.
The first part is a poisoning case.
The perpetrator may not have intended to poison Ying Xiaoya, as the poisoning method involved Yu Hui's chocolate. Knowing that Yu Hui frequently gave Ying Xiaoya chocolate, the poisoner switched the filling, creating a 50% chance of poisoning Yu Hui and a 50% chance of poisoning Ying Xiaoya. The identity of the poisoner and their motive remain unknown.
However, it is certain that his method of poisoning was not intended to directly kill Ying Xiaoya.
No one would eat dozens of chocolates in one go. Half a bottle of organophosphates was scattered among dozens of chocolates. The toxin content in each chocolate was not enough to kill a person, but it was enough to attract attention—perhaps the poisoner was trying to remind someone of something through this method.
Excluding Yu Hui, he loves chocolate and has no motive to poison his sister. Yi Ru and Xie Xinghe are suspects; the lab door locks were broken, and all the teachers who knew Yu Hui frequently delivered chocolate to Ying Xiaoya are also suspects.
The second part of the case is the case of falling from the building.
Yu Hanjiang inspected the rooftop scene yesterday. The footprints on the rooftop were disordered, strongly suggesting the presence of a second person. This person pushed Ying Xiaoya off the building, directly causing her death. Furthermore, this person cleverly copied the handwriting to forge a "suicide note" for Ying Xiaoya, creating the illusion of her "suicide."
This person is the one who truly wants Ying Xiaoya dead!
Unfortunately, he/she did not know that Ying Xiaoya had been poisoned before she fell from the building.
When the police took the body back, they found that Ying Xiaoya had been poisoned. This allowed the police to quickly rule out the possibility that Ying Xiaoya had committed suicide—the forged suicide note of Ying Xiaoya by the murderer became the biggest blunder.
Forensic Doctors investigated the source of the poison, and the police identified Chocolate, organophosphates, and the laboratory as suspects, all pointing to chemistry teacher Qin Weiwei.
Although Ms. Qin was taken away for investigation, the police will soon conclude that she is not the murderer.
Because it doesn't make sense.
No one would be foolish enough to administer a small amount of poison first, then push the person off the roof and forge a suicide note.
The case will be broken up soon.
One person switched the chocolate filling, which contained poison, while another pushed Ying Xiaoya off the rooftop. Because neither of them knew the other's actions, a huge misunderstanding ensued.
Yu Hanjiang glanced at Xiao Lou and said, "Last night there was a downpour, and the school is in such a mess. There will definitely be a large-scale cleanup of the campus today. The murderer may destroy evidence, so we need to do it before the murderer does."
Xiao Lou also tensed up: " Captain Yu, where do you want to search?"
Yu Hanjiang: "The biggest trash can in the corner of the school."
***
Small trash cans are installed inside the teaching and office buildings of Fenglin High School. The trash that students clean up every day is first collected in these small trash cans, and then the cleaners collect the trash into the trash bins behind the playground.
This trash can should be emptied every two to three days, and a professional garbage truck will come and take everything out.
Last night, due to the strong wind and heavy rain, the campus was in a mess. This morning, after the cleaners swept the playground, they collected a large amount of leaves, broken branches, broken flower pots and other garbage into the trash can. The trash can is already full, so we will definitely have to call a garbage truck to empty it.
When Yu Hanjiang and Xiao Lou arrived near the trash can, the sanitation workers were just collecting the trash.
Xiao Lou quickly stepped forward and said to the cleaner, "Auntie, I'm sorry, I'm a teacher for the first year of high school. I accidentally threw a very important document into the trash can yesterday. Could I look for it here?"
The cleaning lady said, "Oh, what document? It's too dirty here, teacher, please don't touch it. We'll help you find it."
Xiao Lou said nervously, "It's my teacher's certificate. I threw it away without looking carefully when I was throwing away trash yesterday. Could you please help me find it? I'll wait here. Thank you."
Yu Hanjiang: "..."
Professor Xiao's acting is quite good.
With this reason, the two could openly stand next to the trash can and observe.
As the cleaning lady rummaged through the trash, she helped the two men look for their certificates, muttering, "You should check them when you throw away trash from now on. What if you can't find such important documents?"
Xiao Lou nodded: "It was my oversight."
Just then, Yu Hanjiang's eyes narrowed sharply: "Wait."
The cleaner was taken aback: "What's wrong with the teacher?"
Yu Hanjiang walked over, not minding the dirt, and picked up a pair of shoes from a pile of waste paper and messy leaves.
It's a pair of women's canvas shoes, size 37, the same as Ying Xiaoya's shoes.
Upon seeing this, the cleaner couldn't help but exclaim, "Who lost these shoes? They look quite new!"
Yu Hanjiang and Xiao Lou exchanged a glance.
Important evidence has been found.
The reason Ying Xiaoya's footprints on the rooftop were so messy was because there were two people's footprints—the other person was wearing the same shoes as her. And the fragments of her scarf left on the rooftop must have indicated that there was a conflict between the two before she was pushed off.
The murderer threw the ill-fitting shoes into the trash can because he knew the school's trash cans would be emptied that day.
Once the garbage truck takes the garbage away, there's no way to prove anything.
Unfortunately, Yu Hanjiang and Xiao Lou found the shoes.
This proves that their previous inference was correct.
In Ying Xiaoya's case, two murderers were acting simultaneously!