Did you find a clue after wandering around for a while? Liu Hongsheng looked unconvinced. He has been engaged in criminal investigation for many years, and his professionalism is among the best in the entire Luzhou City Criminal Police Team. He has looked at all the places he needs to look at, and has not missed anything. , no valuable clues were found, what could he, a layman who graduated from the Department of Political Science and Law, see?

I am indeed not a criminal investigation major, but we have a plug-in. There were no witnesses at the time of the crime, but there were street trees outside the house. Shen Long was leaning on the street tree just now to smoke, and he had already asked the street tree what happened. , it will be much easier for him to search for evidence based on the events of the case. It is not surprising that he can find something useful so quickly.

"According to the information in the file, the male owner of this house is frugal by nature. I just looked at the ashtray. Most of the cigarette butts in it have reached the filter. Only one of them has a long cigarette butt left. This It obviously does not fit the personality of the male owner, and it is most likely left by the criminal suspect; according to the interrogation results, the suspects we have found have denied ever entering this house, so as long as we can find this cigarette butt, it is that suspect The one left behind must be him who committed the crime." Shen Long learned from the street tree that the suspect smoked a cigarette before committing the crime and threw the cigarette butt in the ashtray.

"But how can a small cigarette butt determine who is the murderer? I remember that these criminal suspects all have the habit of smoking. This is not a murder weapon, and there is the suspect's blood on it." Liu Hongsheng still didn't understand. Even if the cigarette butt was really left by the criminal suspect, there is no way to convict him through this. He thought for a moment and asked, "You mean to use this detail to interrogate those criminal suspects again? Take some measures to get them to plead guilty?"

In any case, Shen Long also found clues that he had not found. Liu Hongsheng's tone changed unconsciously. For an old detective like him, capable people are worthy of respect.

"No, we don't engage in illegal things when handling cases." Shen Long knew what he meant by the measures. Sometimes the criminal police team is cornered and it's normal to do something like extorting a confession. This method also has a certain effect. However, it is easy to create unjust, false and wrong cases, so Shen Long is not willing to take this approach.

What's more, this method is against the rules. If others do this, Li Mingjian may turn a blind eye. If he dares to do it, Li Mingjian will definitely take the opportunity to drive him away. He not only wants to solve this case, but also Use absolutely legal methods to break it.

"You go back and pack your things, and I will go on a business trip to Shenghai with me tomorrow. You may have to stay in Shenghai for two or three days." Shen Long lowered his head and got into the car and said to Liu Hongsheng.

"Why are you going to Shenghai?" Liu Hongsheng was even more confused now. Could it be that the real murderer has been controlled by the Shenghai Public Security Bureau? This time, the criminal was escorted back to Luzhou City?

"You'll know when you get there." Shen Long did not reveal any more information. He still didn't know the details of Liu Hongsheng, and he couldn't guarantee whether telling him the truth would cause any surprises.

After returning to the bureau, he told Li Mingjian that he was going on a business trip to Shenghai. Li Mingjian immediately agreed. He didn't think Shen Long's trip to Shenghai at this time had anything to do with solving the case. He wished that he could stay in Shenghai as long as possible. , when the deadline for the 7.23 major case is up, it will be time for accountability. Before that, his leaving Luzhou City will definitely not be conducive to solving the case.

I went down and made some phone calls, made some preparations, and returned to the dormitory to rest for a night. In the afternoon of the next day, I took Liu Hongsheng on the train to Shenghai, slept in a hard sleeper all night, and arrived on the morning of the third day. Shenghai.

"Captain Qi, here we are!" When he came out of the station, he saw Qin Siyuan waiting outside. Next to him was a policeman in police uniform.

"Here, let me introduce to you. This is Comrade Qi Tongwei, the detachment leader of the Luzhou City Criminal Police Detachment. Team Qi, and this is Officer Lu Husheng of the Shenghai Public Security Bureau." Qin Siyuan introduced them.

"I've heard about Captain Qi's name a long time ago. I'm glad to meet you." Lu Husheng shook hands with him enthusiastically. The title of first-class hero model is still very popular in the system.

Shen Long also introduced Qin Siyuan's identity to Liu Hongsheng, and then the four of them got into the police car brought by Lu Husheng; Qin Siyuan was notified by Shen Long, and what he was going to do this time was extremely newsworthy, and he also knew that there were people in the system When working inside, you must not only know how to make meritorious deeds, but also determine where the credit belongs to avoid being robbed by others.

If he solved the case silently, it would be difficult to guarantee that Li Mingjian would not give the credit to others. It would be different with Qin Siyuan by his side. When the time comes, he would write an article and publish it in "Public Security Communications", and the credit would be confirmed. .

"Qi Dui, should we go to the guest house to rest first, or?" Lu Husheng asked as he started the car.

"Go directly to the DNA laboratory and get down to business first." Shen Long replied. The purpose of his coming to Shenghai this time was to use DNA testing technology to determine who the murderer was. Currently, there is no DNA identification technology in China. It is widely used in criminal investigations. Only the public security systems in Shenghai and three other places have DNA laboratories, so Shen Long made a special trip.

"What does this DNA laboratory do?" Liu Hongsheng was confused.

"This is a very advanced technology that has won the Nobel Prize. Human chromosomes are made of DNA. Each human cell has pairs (46) of chromosomes, and the human body has about 3 billion nucleotides. The chromosome system constitutes the entire life, and the exchange and combination before the formation of reproductive cells are random; if they are not identical twins, no two people in the world have exactly the same sequence of 3 billion nucleotides. This is the theoretical basis for DNA comparison and identification." Shen Long read this detail from an online novel called "Police Officer Han", but he didn't expect it to come in handy here.

"Cigarette butts contain the smoker's saliva and oral epithelial cells, which can be compared with the suspect's hair to determine the smoker's identity." Shen Long took out the evidence bag, "It was used in the UK as early as 1984. DNA technology solved a rape and murder case. This technology is booming in Western developed countries and is widely used in criminal investigations. There are cases of DNA identification in the United States and the United Kingdom. The Shenghai Public Security Bureau has just established a DNA laboratory, which can Take this test.”
Chapter completed!