The most important thing in solving a poisoning case is to determine where the source of the poison comes from, and basically by determining the source of the poison, the nature of the poisoning case can be determined.

The nature of poisoning cases is nothing more than three kinds, the first is self-poisoning, the second is accidental poisoning, and the third is poisoning by others.

Strictly speaking, the first case is self-harm, the second is an accident, and only the third is a criminal case. Therefore, the police must rule out the first two situations before they can conduct a criminal investigation.

After confirming that the deceased died of poisoning, Huang Qiqi immediately wanted to find the source of the poison, and this idea of handling the case was also correct.

The forensic examiner immediately began examining the food and drinks on the table. Huang Qiqi continued to ask the deceased's friends.

"Have you noticed any unusual behavior of the deceased lately?" Huang Qiqi asked.

Everyone shook their heads, and Huang Qiqi continued to prompt: "If you think about it carefully, it seems that there has been a change in mood, becoming irritable, restless, panicked, nervous, and so on. ”

Huang Qiqi wanted to know whether the deceased had suicidal tendencies. After all, the life of Xiangjiang people is stressful, and many people have mental problems, and it is not new to suddenly choose suicide without thinking of it.

Teaching assistant Xue Youlin immediately spoke: "Sir, does too much pressure on schoolwork count?" As far as I know, Yu Zhenghuang has been writing his graduation thesis recently, but it doesn't seem to be going well. ”

"How is it not going well?" Huang Qiqi immediately asked.

"I don't know the specifics, I'm just a teaching assistant, and it's not enough to guide graduate students to write dissertations, and dissertations are personal research results, so I can't ask too much detail."

Xue Youlin paused, and then said: "Actually, the thesis is not written smoothly, and it is a common thing in school, and many students are worried about their graduation thesis. When I got my degree, I was worried about my thesis every day! ”

Huang Qiqi nodded, and then asked: "According to your understanding, did the deceased Yu Zhenghuang have a feud with anyone?" ”

"I don't know much about that. Lin Zhijian may know that the two of them attend classes together every day. Assistant teacher Xue Youlin replied.

Lin Zhijian hurriedly stepped forward: "Sir, Yu Zhenghuang shouldn't have any enemies, I have the same mentor as him, and we study together every day, and I haven't heard that he has any enemies."

And we are all students, we have not entered the society, and we do not have too complicated interpersonal relationships, usually it is the two points and one line between home and school, and it is impossible to offend any enemies. ”

"Did the deceased's family have a huge debt?" Huang Qiqi then asked.

"I know a little bit about this, his family background is not good, it is not bad, his parents are ordinary office workers, I can't remember exactly what he did. However, I have not heard of him being in debt. Lin Zhijian replied.

"That is, the family is harmonious, and the parents are alive." Huang Qiqi then asked: "Did the deceased have any emotional disputes?" ”

"He's single, and he's broken up with his ex-girlfriend for almost half a year! I don't know who dumped whom, but I haven't seen his ex-girlfriend to pester him in the past six months, and he hasn't had anything to do with his girlfriend in advance, so it should be a good get-together. Lin Zhijian replied.

Huang Qiqi asked these questions, in fact, to judge how likely it is that the deceased committed suicide.

For example, depression, falling out of love, being asked for debts and seeking revenge, etc., will be the reasons for suicide, so Huang Qiqi also focuses on this aspect of inquiry.

He Jiahui next to him really couldn't stand it, Huang Qiqi asked for a long time, but he didn't mention the core question.

So He Jiahui directly asked the forensic evidence: "Is there a container for cyanide found on the deceased's body?" ”

This forensic evidence is the forensic evidence of the last murder case in the cafeteria of the police academy, he turned his head to glance at it, and said in his heart that this is not the cadet policeman who solved the case in the police academy!

Looking at the police officer card on He Jiahui's chest again, he knew that he had graduated and was now a full-fledged policeman.

Since the other party was a regular police officer, there was no doubt about revealing the facts of the case, so the forensic witness said: "On the deceased, no container for cyanide was found. ”

"Did you find it on the ground or in the corner of the couch near there?" Ho Ka Fai then asked.

"No, I've seen all the corners and couch crevices, and there are no suspicious objects." Forensic replied.

He Jiahui nodded, turned his head to Huang Qiqi and said, "Then there is a high probability that it can be concluded that the deceased did not commit suicide!" ”

"How do you know it's not a suicide!" Huang Qiqi asked.

"If the deceased committed suicide, then why can't he find a container for cyanide on his body? He can't conjure cyanide out of thin air! He Jiahui replied.

"Maybe the deceased threw the container away!" Huang Qiqi argued.

"Where to throw? You should know that after taking cyanide, it will attack in two minutes, and if you throw away the container where cyanide is stored, it will definitely not be far away. But I didn't find it nearby. ”

He Jiahui paused, and then said: "Besides, if the deceased is about to commit suicide by taking poison with poison, how can he have the heart to hide the poison!" ”

Huang Qiqi was speechless, but he also had to admit that the deceased did not commit suicide by taking poison.

"Since it wasn't a suicide, it's very likely that he killed it." Huang Qiqi looked at the deceased's friend and asked, "Have any of you ever left before?" Like going to the toilet or something. ”

Everyone looked at me, I looked at you, and shook their heads one after another, indicating that they didn't leave.

At this time, the forensic side also gave the result.

I only heard the forensic evidence say: "I have examined the food on the table, and I have eaten the leftover birthday cakes, durian crisps, cream cakes, egg tarts, potato chips, and fruits, and no toxic reactions have been found in any of the foods.

In addition, I have tested the plastic knife for cutting cakes, the box for durian crisp, cream crisp and egg tarts, and the plate for potato chips and fruits, and found no toxic reactions.

In the end, I checked the beer on the table, and only the can of beer in front of the deceased found a reaction to cyanide, and no one else's beer found a reaction of poison. ”

"In other words, the source of the poison is the can of beer that the deceased drank!" Huang Qimeng asked, "Where did this bottle of poisonous beer come from?" ”

"We ordered the wine and the waiter brought it to us." Someone immediately replied.

"The waiter in charge of serving the wine at this table, get someone quickly."

Huang Qiqi gave an order, and the waiter was immediately called over.

"Sir, wronged, I didn't poison it!" The waiter explained miserably.

"Don't be nervous, I didn't say you were poisoned." Huang Qiqi continued: "I want to ask you to carefully recall the process of giving wine to this table, all the details must be explained clearly, and you must not hide anything, which is also good for you." ”

The waiter thought for a moment and replied, "There are seven people at this table, and I also ordered seven cans of beer, and then I went to get the beer, put it in the ice bucket and brought it over." When I took it, the beer cans weren't even opened! ”

"Did you meet anyone or anything in between? Has the beer ever left your sights? Huang Qiqi then asked.

"The beer is chilled, and if the ice melts, the taste will not be good, so I didn't delay after I got the beer, and sent it directly to me, without stopping in the middle, and the ice bucket was always in my hands and never left my sight." The waiter replied.

"Okay, go on, what about after you bring the wine?" Huang Qiqi then asked.

"I put the ice bucket on the table and said that the beer you ordered had arrived, and then the beer they took from the ice bucket themselves, and the beer cans they opened themselves, and after the beer was delivered, I left." The waiter replied.

"That is, the beer was taken by themselves, and not by you to everyone?" Huang Qiqi continued to ask.

"That's right, they took it themselves, and I didn't touch it the whole time." The waiter nodded.

Huang Qiqi nodded slightly, if the waiter's description is correct, then the waiter's suspicion of committing the crime can basically be ruled out.