Panda Criminal Investigation Team

The books taken from Li Qianqian were proved to be free of toxins,

Only cold germs and human saliva were found on it,

Thallium sulfate or any other thallium-related chemical constituents were not detected.

Since Yang Ying is the only person around Li Qianqian who can obtain thallium sulfate,

clashed with it again,

The police issued a search warrant,

Conducted another major inspection of the girls' dormitory,

But no clues were found.a few days later,

The superior issued a search warrant against Yang Ying's hometown, and with the cooperation of the local police, police officers from the second team entered Yang Ying's home to collect evidence.

Nothing was found either.Even the Internet police retrieved Yang Ying's online records for several months, but found that in her computer records, even the word "thallium" did not appear in the search term.

"Can't find anything,

Do you think Yang Ying is innocent? "

Cheng Bin holds a mug,

Stick it on Yu Renjie's cubicle and ask him.Yu Renjie likes to close the door as soon as he gets home, so Cheng Bin took advantage of working hours,

Ask for his opinion on almost every case.

"Two possibilities." Yu Renjie replied, resting his chin: "First,

she is really innocent,

Everything is a coincidence.second,

This little girl is very thoughtful,

Anti-reconnaissance capabilities are particularly strong,

Maybe people go to Internet cafes to check information, right? "

Cheng Bin nodded, picked up the cup,

found that the tea was too hot,

Put it down again: "I think it's the second type, what do you think?"

"Well, I think so too."

"How about the exercise book?"

"The little girl was stubborn and insisted that the exercise book was lost on the way back from the hospital, so she bought a new one and returned it to the library. But looking at the date, she found out that she lost the new book the day after it was dropped. It is obviously prepared. Of course, this does not mean anything, maybe they have a sense of responsibility, right?"

"Is that book still available?"

"No, you should ask, are those books still available?"

Yang Ying gave the library a total of three books, two of which were in Li Qianqian's name and one was in her own name.Later, Li Qianqian went back to the dormitory and found that another novel that Yang Ying lent her was missing, so at least four books disappeared.

So Cheng Bin corrected, "Can those books still be found?"

"I guess I can't find it. If it was Yang Ying who poisoned her, how could someone who can even manage Internet records leave books covered in poison|drugs for us to check? I guess she found a place to bury the books, Just set a fire and burn the book."

After listening to his reasoning, Cheng Bin commented: "It's really not scary to be a hooligan, but I'm afraid that hooligans are educated."

"You can be considered a bit of a culture..." Pushing the context, Yu Renjie covered his mouth belatedly, but nothing happened, because Cheng Bin cooperated to pretend to be deaf and dumb.Guiltyly, he picked up the cup and took a sip of the freshly brewed tea, which made him cough until he covered Yu Renjie's words, and Yu Renjie took the opportunity to say something else and brought the topic over.

After Cheng Bin finished coughing, he took the tissue handed over by Xi Shi and wiped his mouth: "It may not be a bad thing if nothing can be found out now, if it is as we guessed before, if Yang Ying has not had time to discard the evidence , then the evidence must still be hidden somewhere, waiting for us to find it.”

Yu Renjie finally raised his eyes and glanced at him: "This sentence is considered to be a bit level for you. Even if the book is burned, there will still be poison | medicine. Among the four books that disappeared, one is a novel and two are novels. The teaching references that will be used in the exam stage of the first semester, and the textbook that will be used in the new semester. From this, it can be judged that at least until the beginning of the new semester, Yang Ying has not stopped poisoning. Li Qianqian also said that this semester Yang Ying Ying was the first to live in the dormitory, a whole week earlier than the start of school, which can be used to do some bad things... According to her extensive poisoning and perseverance, she will not use the poison|drug before the Dongchuang incident. Discarded."

"Just in case, I mean just in case, the poison|drug has already been disposed of by Yang Ying..." Cheng Bin's mouth twitched, revealing a sarcastic smile: "We will stop cooking, and we have no evidence. It's the perfect crime."

But Yu Renjie stretched out his slender fingers and shook him: "I don't think so, because when I went to search their dormitory last time, Yang Ying drank seventeen sips of water in 5 minutes..."

"Don't work hard during the search, do you still have time to count this?"

"When people are nervous, their mouth and tongue will be dry, and they will do more small movements. When there is a glass of water in front of them, drinking water solves two problems at the same time-after drinking seventeen sips, she is very guilty. But I am really not free , so I only watched her for 5 minutes."

"Forget it, you're going to talk nonsense." Cheng Bin smiled at him, but immediately covered his smile: "What do you think is the reason why she didn't abandon the evidence for so long? The police did search their household garbage regularly, but They were not being closely monitored, and she had time to deal with the evidence before the police got involved, as she had with the books."

Yu Renjie tilted his head and thought for a while, then said, "I don't know."

Cheng Bin was stunned for a moment, then lowered his head and blew on his tea: "Maybe she thought that no one would think that books are murder weapons, so she dared to take books out of the house openly. But poison | medicine is different, no matter what It’s suspicious enough to pretend anywhere. It may be that she thinks highly of us too much, thinking that we have eyeliner all over the place, so she dare not discard the incriminating evidence casually-this is also understandable, young people nowadays watch too many American dramas. "

He felt good about himself, thinking that the last sentence would be a joke, but Yu Renjie didn't laugh at all. Instead, he said seriously: "Yang Ying is cautious and suspicious by nature. Let’s get rid of things after the wind has passed.”

Cheng Bin was dissatisfied with his reaction, and snorted, "I've only heard of committing crimes against the wind, but I've never heard of abandoning things against the wind."

"Anyway, that's what it means." Yu Renjie rolled his eyes at him: "But in case, I mean in case, she had already cleaned up everything before Li Qianqian was found to have thallium poisoning by the hospital, we should stop cooking."

"Having said so much, it's still not the same as my conclusion." Cheng Bin's mouth twitched obviously, and he blurted out: "What nonsense are you talking about? It's all fart! You fart!"

At this moment, Pan Wei pouted his buttocks and got out of his ass. Amidst the huge sound of "噗嗤", everyone hid and fled. Cheng Bin also slipped back to his little room under Yu Renjie's condemnation. Room.He himself didn't understand why he was so vulgar just now, he kept talking about farting, and he didn't understand why he said it, and the fart followed.

After a while, Cheng Bin quietly opened the door of the office and glanced in Yu Renjie's direction. The power of the fart seemed to have passed, and the team members returned to their seats, and Yu Renjie was already lying on his desk. rest.Only then did Cheng Bin feel relieved, closed the door, and began to think about the whole case.

Judging from Yang Ying's reaction, there should be evidence of the crime, probably hidden in the girls' dormitory.However, the police have searched the dormitory three times, and still have not found anything. Is the incriminating evidence hidden in the dormitory, where is it hidden, and what could it be?Is it really the remaining poison|drug as they guessed?

In the laboratory of X University, there are both thallium sulfate powder and thallium sulfate solution prepared by the experimenter. Stealing the solution directly is easier, but stealing the powder is more difficult to detect.Generally speaking, both solid and commercial items are considered suspicious.

Later they had an internal discussion about where the poison might be hidden.

Xi Shi guessed that Yang Ying had sewn the vessel containing the thallium sulfate powder into the quilt so that no one could find it.On this basis, Xiao Mi made a more imaginative hypothesis. Pointing to her chest, she asked whether Yang Ying would seal up the poisonous solution with waterproof cloth, and then sew the poison into the chest pad, Then it will be invisible.Now there is a bra on the market, which claims to be able to lift two cups directly, and the stuffing inside is silicone, which is fluid, similar to water.What's more, Pan Wei said, the poison|drug may be hidden in the sole of the shoe, put together with the height-enhancing insole, who knows where the insole is and where the poison|drug is...

Cheng Bin ruthlessly rejected all their conjectures: "Thallium sulfate can enter the human body through skin contact. If you dare to put this thing on the sole of your shoe, sew it into your quilt, stuff it in your, your... what here!"

Halfway through the discussion, Hao Jinyang took the lead in putting forward a constructive hypothesis: "Is it possible to put the thallium sulfate solution in a plastic bag and tie it into the toilet tank?"

So far in the search, the police did not remove the quilt, dig out the insoles, remove the cover, let alone open the water tank of the toilet.And it is indeed possible to hide things in the toilet tank. In Hong Kong dramas, it is a treasured place where drugs and pistols are often found.

All suspicious liquids and solid powders in the dormitory have been sent for inspection, including girls' lotion, facial cleanser, washing powder, prickly heat powder, etc.Cheng Bin submitted a new search warrant application on the grounds that the hidden place had not been opened, and decided to conduct a thorough search of the girls' dormitory again.

The investigation order came down soon.On the way to X University, Cheng Bin raised a question. If what Yang Ying used was indeed thallium sulfate powder or solution from the laboratory, why didn't she just pour it out, because she was afraid that the police would detect it in the sewer? Thallium ions?

Regarding this question, all the team members shook their heads. This is exactly what they were wondering about.There were times when they questioned whether another dorm search was necessary, but actually, disposing of the colorless, odorless liquid or powder was not as difficult as one might think.For example, Yu Renjie proposed that if it was him, he would bring the highly poisonous bottle into the public toilet, pour the poison into the urinal and flush it away, and then discard the bottle.Even if the toxin in the bottle is found by the police, as long as there are no fingerprints on the bottle, no one can prove who the bottle is.The most thoughtless way is to pour the reagent directly into the dormitory. Even if the bottle is not discarded, as long as it is kept cleaning, it is still possible to get away with it.

Now the most advanced experimental instruments in our country, the detection limit of ions is generally around 10 μg/L, that is, the ion concentration in each liter must reach 10 minus 6 grams to be detected by the instrument.Judging from the remaining capacity of thallium sulfate in the laboratory, considering that the missing amount did not attract the attention of laboratory personnel, the actual stolen solution did not exceed 20 milliliters, and the powder did not exceed 5 grams.According to this theory, as long as it is repeatedly diluted and rinsed continuously, it is also possible to clean up the items that have been in contact with thallium persulfate.

From another point of view, the solubility of thallium sulfate in water is not high, and the saturated solution at room temperature only contains 48.7g of thallium sulfate per liter, of which thallium ions are 39.3g.If the police's judgment is correct and the poison was indeed placed on the pages of the book, then the active ingredient of sulfate on each page is very small, and then it was brought into Li Qianqian's mouth by her fingers, and finally entered through her saliva. Her toiletries and tea utensils were diluted again. At this time, even though Li Qianqian's body and mouth contained deadly poison, thallium ions may not be detected on her daily necessities, and the content may have been lower than the detection of the instrument. limit.

So far, the poison enters from the mouth but has not been detected on the objects in contact with the mouth, which makes sense.