Bai Luoling saw a figure in front of the boss's office walking in at this time, and saw that the back image was Li Aya, but she didn't care about other thoughts, for example, who invaded her computer, who was interested in what information in her computer, secretly went to investigate at night, maybe there was a pair of ghost-like eyes staring at her. Bai Luoling's thoughts were only for a moment, and the clouds that fell into confusion immediately recovered, and he followed Liu Leilei downstairs directly.

Over there, Li Xiaolan put a bunch of snacks into her drawer, chewed on a bag of something, shook her head like a rattle, and said I won't go.

After several days of continuous rain, in the weather without haze, the sun came out, and it was difficult to shoot things that were seen with the naked eye on the mobile phone, and the mobile phone had not been cleaned up for a long time.

The three of them hit a car, Liu Leilei sat in the front co-pilot's seat, Bai Luoling inadvertently glanced at the rearview mirror from the back, and felt that Liu Leilei seemed to be thinking about something, and his eyes were in a trance.

"There will be people waiting for you in the wind and rain. He will go out of his way to hug you, he will take you to the sun to dry the years, and you will remember him alone. Looking at the flowing street scene outside the car window, Liu Leilei hummed a song casually, the tune was similar to the style of campus folk songs.

Bai Luoling sorted out the expression on his face, and asked Liu Leilei quietly and calmly: "Who sang this song, it's so good" Liu Leilei looked back and replied with a smile: Xiao Shuai, I learned to play the guitar in my junior year and wrote some songs by myself.

As soon as they arrived at their destination, the two of them got out of the car together, and happened to meet Xiao Shuai and other police officers who parked on the side of the road together, and brought down an emaciated woman from the car.

Interrogation Room 1. Sitting opposite Xiao Shuai was a woman in her twenties. Bai Luoling and Liu Leilei looked through the glass, and there was no trace of immaturity on her. Lifting the wandering eyes gives people a sense of unease. The bright light made her squint her eyes and look terrified.

"Name?"

"Wang Xiaoyan"

"Age?"

“28”

"How long have you been on drugs?"

"I didn't"

Xiao Shuai stopped the pen he was recording in his hand, raised his head and glared at her with a serious expression, and repeatedly lifted her sleeves to reveal the inside of her elbow full of bell holes in the blood vessels.

"More than a year" The woman gave up quibbling at this time.

"Do you know this person?" Xiao Shuai said, pointing to Li Xinyi's photo.

"Meet our regular customers at the beauty salon"

"On the day of the crime, you went to the open-air balcony on the 24th floor of the company with the deceased, the deceased fell down the stairs at 10:45, and you left at 10:47......

This is what may have happened to the sound transmission system across the interrogation room, emitting a sizzling electric sound, Bai Luoling asked Liu Leilei curiously: How can you judge the height of the suspect by footprints?

Liu Leilei measured his steps back and forth: "Well, the basic knowledge that will be learned in the line investigation, there are mature mathematical formulas to calculate, the first one, the height of the plane barefoot is equal to 7 times the plane barefoot footprint, and the three-dimensional barefoot height analysis formula is: height H = (the length of the three-dimensional barefoot foot minus the length difference between the three-dimensional and the plane footprint, and then multiply by 7)"

Bai Luoling hurriedly asked again: "What about the second type?" ”

"If the height is inferred from the shoe number, the height of the suspect is the shoe number of the person wearing the shoes multiplied by 6.875, of course, the gender can also be judged from the footprints, because the gender is different, the physiological structure of the person is also different, the motor function and the wearing decoration are also different, they can be reflected in the footprint, the male limbs are developed, the bones are thick, the pelvis is high and narrow, and the female pelvis is low and wide....." When it comes to professional knowledge, Liu Leilei is like a bamboo tube that can't be stopped, a thunderbolt, she was about to talk about gait characteristics, when she saw the security officer of the electronic forensics department coming over.

"Xiao Liu? What day is today, are you waiting for Xiao Shuai to get off work? Officer Wei greeted Liu Leilei gently

"Well, this fall is on the 15th floor of the building of my internship unit, which is also one floor above our magazine, I want to come and find out, so as to be vigilant, this is Bai Luoling, my colleague."

"Oh so, there is no final result yet, I can't do any public reporting, Xiao Shuai is interrogating an important suspect inside, we found the handprint of the technician of this beauty salon in the evidence collection office, the type of papillae pattern is in the form of a tent pattern, the upper arch line is large, and the lower wavy line is layered, just Wang Xiaoyan is matched, and through monitoring, she did go to the rooftop with the deceased at the time of the crime, and from the deceased's bank card records, it was found that the deceased had some transfer records with Wang Xiaoyan......"

"Anything else you've found besides that?" Liu Leilei asked

There is also a middle-aged man's handprint, but from the mobile phone contacts and colleagues in the unit, these people who have frequent contact or dealings with have never been able to find this person with the corresponding palm print, but ...... I found a forbidden song in my phone."

"Black Friday?" Bai Luoling and Liu Leilei said in unison.

"What, do you understand? Although there are real cases in the world of this black music murder case, it is not enough evidence to convict, so we can only follow this clue to find other doubtful motives."

Bai Luoling recalled the music restaurant where he gathered that day, looked at Liu Leilei and the police officer and said: "The last time we had dinner at a music restaurant in the Super Brand Mall, we chatted late, and a very strange singer sang a particularly sad ...... with an exotic voice."

"I've heard all kinds of Black Friday, but I don't know how strong the impact of the original is, there is a saying: the real piece of music has long been extinct, its original name is "Magic Music", not by one person, but by a group of music masters. None of the people who actually heard this song survived, it uses infrasound waves and other means to stimulate the nerves of the cerebral cortex, and the human brain and infrasound waves with a frequency of 20HZ can resonate, which is not something you can restrain with willpower at all."

Officer Wei said: "Our criminal investigation department is handling the case, it is talking about realistic evidence, if it is really because of music that he committed suicide, such a bizarre case will be compiled into the history of anecdotes."

Liu Leilei grabbed the topic and said: "I finished reading a comprehensive textbook called "Skeleton Talking" by Mr. Wang, a professor of criminal investigation at the Public Security University, but it is full of realistic cases, and when I graduate, I will draft a record of detectives, including all kinds of strange cases I have experienced, and write a contemporary "Record of Clearing Grievances" like Song Ci, the originator of our law."

Officer Wei scratched Liu Leilei's nose and said fatherly: "You little ghost, you and Xiao Shuai are really a couple... Uncle Wei wishes you all the best in your studies in Hong Kong."

Bai Luoling thought to himself: "If you want to write a secret record, you have to find my grandmother."

On the way home, Bai Luoling's mind returned to the case on the mobile phone, Li Xiaolan, the tomb robbery gang found in the suburbs two years ago, the leader is called Li Zheng, Li Xiaolan is Li Zheng's own daughter, Li Zheng's gang was sentenced to 7 years in prison for reselling cultural relics, she went to the morgue that night and said that she was afraid that she would go home first, but her computer was invaded, Li Xiaolan is a computer learner, it may not be difficult to crack the administrator password, maybe it is Li Aya, in order to know that she and Liu Leilei have been in and out frequently in the past two days and want to peek at the progress of the case, oh, yes, In the morning she went into her boss's office

Bai Luoling didn't want to go home, so she went back to the office to see who wanted to peek at her computer information, so she went back to the company alone, sat behind the glove cabinet and waited for the rabbit.

At three o'clock in the middle of the night, the pajamas made Bai Luoling fall asleep in a daze, and at this time, there was a burst of footsteps at the door of the office, and Bai Luoling pricked up his ears and was highly alert......