At half past eight, a group of six people stepped into the gate of the Yecheng Police Station on time. The Director and the Inspector, both low-ranking civil servants, carefully welcomed the "Finance Officers" into a small, slightly cramped and gloomy conference room.

The director and inspector are all in their thirties, and they are strong and capable. Federal civil servants are extremely well regulated, not well paid, and more of a symbol of honor and status, usually from well-to-do families with clean backgrounds, requiring higher education, and of course nothing superfluous happens.

After a little greeting, Lin Zhenna, as the number two person in the team, said to the other party; "Although Mr. Director Fan is going to handle official business, we are here to take over Case No. 1011007 and complete the personnel delivery of trainee police officer Sun Yanyan by the way. Inspector Qin can accompany the handover. ”

Director Fan didn't turn around and leave immediately, but looked at Sun Yanyan gently, turned to Yu Bule and said earnestly: "Yanyan, this child was grown up by the two of us, and it was her luck to have the honor to follow the chiefs today." It's just this kid...... This kid didn't go to a public school, and if he went to the capital area and did anything inappropriate to offend Shangguan, he also implored the governor Hai Han to do one or two. If she is found guilty, she can be sent back to Yecheng Police Station. Offended, sir. ”

Director Fan bowed and saluted Yu Bule.

Yu Bule leaned sideways slightly, "The chief is his father and brother, and Director Fan is sympathetic to his subordinates, and he is really a model for my generation." Sun Yanyan will be appointed fairly. ”

Director Fan also knew that he had talked too much, so he left with a confession.

Yu Bule said to Inspector Qin again: "I have read the case file, since the investigation record was made by Sun Qian's trainee investigator, please ask her to explain the case." Inspector Qin, do you think it's appropriate? ”

Inspector Qin was happy that Sun Yanyan had a chance to perform, and instructed Sun Yanyan in a low voice, and he personally went to prepare the projector, deliberately leaving time for Sun Yanyan to prepare. While apologizing for the crime, the police station is not expensive, the equipment is outdated, and the old-fashioned projector bulb needs to be preheated before the screen can be projected, while adjusting the angle of the reflector, the focal length, and the position of the film.

Sun Yanyan stood next to the projection screen, holding a bamboo whip, and explained the situation of Case No. 1011007 with a slightly nervous and clear voice.

10 represents 610 that is, last year, 1 represents the vicious homicide case, 10 is the month, and 07 is the case number. This is a serial murder case that has already occurred four times, which caused great panic in the local public opinion in Yecheng, but the case could not be solved for a long time, so it was reported to the Investigation Bureau.

On the morning of October 11, 610, in the corner of a dead end in the north city wall, the first deceased was found, the deceased was Zhang Yin, a 32-year-old Liuying in the red light district of Yecheng North District, who had been selling his art in the famous Qinglou Cuiyin Pavilion in Yecheng since he was a child.

After three years of stable life, he also gave birth to a son for his grandson, who was over 60 years old. The old man of the grandson died of illness, and his heirs took the son and drove him out of the house on the grounds of confusing his father. After losing her livelihood, she was half old and still in decay, and went to nightclubs to work as a dancer for 4 years. Because she was trained by the Qinglou at a young age, she was knowledgeable and talkative, and she was famous before, and she was popular for a few years and then suffered an accident, and she was scratched on her face because she fell down when she was drunk, and the ill-fated woman finally ended up on the street and became a warbler in the red light district of the North District. After his death, he found that he had saved 25 yuan, and it was rumored that he was going to buy a small shop in another small county town to make a living.

The poor woman died face down, leaning against the wall, her neck bone was vigorously broken from the right side, and the contusion marks of the neck muscles were analyzed, and it was inferred that the left hand was suddenly twisted. The cheap satin palace dress was lifted, the upper body was not untied, the black thong panties were pushed to one side, the perineum and vaginal v canal should be checked before death There should be sexual v behavior or foreign body invasion friction marks, no semen V fluid residue was found, and the neck was bent and bowel and bowel incontinence naturally, so it could not be accurately judged. The estimated time of death is between 11 p.m. and 1 p.m.

The ground at the scene is a stone brick floor, and no valid evidence information can be found, and the grass stems in several stone crevices and the traces of weeds trampled or crushed by the city wall are also numbered one by one, but no effective evidence can be provided. The only thing worth mentioning is that the scene of the crime is not far from the red light district, but it is at least 500 meters away from the streets.

Usually the warbler and the prostitute V client have an affair, and there are some commonly used remote corners near the red light district, and they will not go to such a remote location, which shows that the murderer is well prepared. The deceased had rented a house in the red light district, and there was no sign of intrusion, and there was no silver hidden in the deceased's house.

Due to the complicated social relationship of the deceased, the extraordinary experience, and the fact that no evidence was left at the scene, the investigation of the police station at that time was very difficult, and a large number of hypothetical investigations were done, but there was no clue. However, it does not belong to the content of the case, and Sun Yanyan did not explain.

Two months later, in the Red Light District of the North District, a second case occurred. On December 24, a second murdered prostitute was found at a similar location in the first case, just over 200 metres away. The deceased was 23 years old, surnamed Hu Fei Fei, whose original name was unknown, was rumored to be a peasant girl in the surrounding county, and after the death of her parents, she began to sell herself in the red light district at the age of 17 because of her average appearance.

The death is very similar to the first case. The difference is that the deceased was dressed as a suit and skirt, flesh-colored stockings, white high heels, and a female clerk. At the time of his death, the shirt was unbuttoned three times, and the skirt was lifted to the waist, which was also a thong, and this time the deceased was a white thong. There is still no valid evidence extracted. However, some witnesses have provided that after 12:30 p.m. the night before, the deceased had been witnessed leaving the red light district alone and walking north.

The time of death was judged to be between 1 a.m. and 3 a.m. the night before. However, the 23rd of the previous day was the Unified Youth Coming of Age Day in all parts of the Federation, and the curfew was two hours later than the usual 10 o'clock. Therefore, the similarity between the two cases should be added, and the time of death is between 1 and 3 hours after the curfew.

So far, the two cases have been combined and called the "Thong Murder of Prostitutes Case".

The third case occurred on March 7 this year. is still a liuying in the red light district of the North District, a woman surnamed Wang, 27 years old. The slight difference is that the place of the crime is no longer the north city wall, but in a hidden bridge under a stone bridge to the south of the red light district. Due to the hidden location, the body was found by children playing in the water only two days after the death due to the water rising after the rain, and the hair floated out from under the bridge hole.

The same is the left hand and neck killing, but the state of the deceased is quite different from the previous two cases. The same is that they were all suddenly bent on the ground and died, but the difference is that the deceased's stockings were taken off this time, and the deceased's hands were tied behind him. With the physique of the Federation people practicing martial arts, even the thin hemp rope could not play a binding role, and the stocking binding did not play any role except to show the murderer's special hobby.

In addition, the death site this time was by the waterside under the bridge, the soil was quite wet, and the deceased had taken off his stockings to put on the murderer again with high heels.

After the murder, the murderer had simply tidied up the scene, pulled weeds to cover up the footprints, and was washed by the rising river, and the scene was quite messy. It is difficult to even determine the time of death, and it can only be accurate until the time period when the deceased left the red light district alone at 11 p.m. on the 7th and the early morning of March 8.

After repeated discussions, some witnesses also found that the victim left alone, and it was determined that the murderer was upgraded and was included in the serial homicide investigation.

The last one was on the 6th of last month, that is, on August 6th, after a lapse of May, another prostitute was killed by twisting her neck, and what is even more excessive is that this time the scene is the first time that a woman surnamed Zhang was killed. The deceased, also surnamed Wang, was only 18 years old, had been in the industry for less than three months, the deceased was naked, her skirt was lifted, her hands were tied with her own stockings, and the knots were tied in the same way as in the previous case, which proved that the previous case was committed by the same murderer.

The Yecheng Police Station was unable to solve the case, and the impact of the case was getting bigger and bigger, so it was reported to the capital. The General Police Department of the Metropolitan Area sent personnel to Yecheng to investigate for more than half a month, but no substantial progress was made, and after the investigation bureau was established, the case was transferred to the investigation bureau.

Sun Yanyan gradually faded from her nervousness, except for some nude pictures of corpses, or the meeting at the location of the sexual act, she seemed to have completely lost her chattering nature, and the explanation was clear, the language was concise, and she told the scene with great precision. The structure is rigorous and rational.

The photographs are limited by the equipment and are very blurry, and more evidence still depends on the description of the evidence number record. From Sun Yanyan's numbering order of each suspected evidence, it can be seen that her analysis and judgment of the scene are accurately described, such as how many grasses are lodging, the direction of lodging, the force mode, the inference of the direction of the murderer's travel, and so on. almost put the scene with no evidence into a story line.

Tan Jiaren immediately understood why the chief decided to transfer the recorder to the prosecutor's office just by looking at the written records, and she understood that this girl was a detective genius.