Jian Jing walked around the crime scene, looking for suspicious points.

The washbasin outside was neither clean nor dirty, with a few strands of hair scattered on the countertop, the faucet was old-fashioned, and two drops of dried lip gloss dripping from the basin.

She remembered this color, it should be Tang Yuran's, proving that she had indeed touched up her makeup.

The bathroom was separated by a door, and there was a mop and bucket behind the door.

She picked it up and took a look, and found that there was red blood under the mop strips. She smelled it closely, and the strong stench covered everything.

Then go to the third cubicle to check.

The scene of Tang Yuran's death was covered with blood, and the scene was very scary, which could scare many outsiders.

But Jian Jing had already acquired some superficial knowledge of trace detection. In her opinion, the bloodstains in the cubicle were full of the word "unscientific".

First of all, Tang Yuran had several wounds on her chest, oozing a lot of blood. There was no murder weapon, and it was estimated that she was stabbed by a sharp weapon.

If this was the first scene, then when the murderer pulled out the murder weapon, a large amount of blood should have spurted out, forming medium-speed impact bloodstains at the scene, that is, blood spurted out under the pressure of the human body.

The diameter of these blood drops is generally less than 4 mm, and they are irregular circles. In addition, there should be tiny blood spots scattered nearby.

But no matter how much blood there is in the cubicle, the bloodstains on the door and partitions are dragging a long tail.

This is a typical flinging bloodstain, which will only appear when a bloody weapon is waved or a bleeding limb is moved.

Was Tang Yuran dancing in the toilet while bleeding?

In addition, most of the bloodstains were wiped bloodstains, one after another horrible bloody handprints.

There were indeed bloodstains on Tang Yuran's hands, but think about it, a person was seriously injured in the toilet, and the instinct for survival would definitely drive her to open the door and go out for help, instead of going crazy and leaving so many bloody handprints in the toilet.

The key is that there was no blood on the door bolt.

The most incredible thing is that after a while, the bloodstains at the scene still have not coagulated.

You know, blood coagulates very quickly. If it hasn't coagulated for such a long time, either Tang Yuran has leukemia, or... this "blood" that looks like blood is not real blood.

Jian Jing took a closer sniff and felt that the bloody smell was indeed too weak. Even

a killed chicken doesn't have such a slight smell.

This is not blood, is it a prop? As far as she knows, sometimes in order to shoot bloody scenes, some specially treated blood is needed, which may be pig blood or sheep blood. After adding anticoagulants, it can always remain fresh.

There was fake blood on Tang Yuran's hand, and when compared with the bloody handprint in the compartment, the size matched.

Jian Jing judged that Tang Yuran had set up such a fake scene for some reason. Maybe she wanted to play a prank? But in the end it became an illusion to cover up her death.

However, in addition to the fake blood, there are a few drops of blood that have dried up and look like real blood.

These drops of blood are about 5 mm in diameter, and are typical drip-like bloodstains. They are very regular circles with some uneven burrs.

In a static state, the burrs of dripping bloodstains are of uniform length, but not in motion.

According to the length of the burrs, the direction of movement can be determined - these drops of bloodstains have shorter burrs near the door and longer burrs near the inside. In other words, these were dropped when someone walked into the toilet from outside.

Whether it was left by the murderer or Tang Yuran, it undoubtedly revealed a reality.

This is not the first crime scene.

The murderer killed Tang Yuran, and then moved her to this pretend murder location, using some tricks to close the cubicle door and pretend it was a crime scene.

Before leaving, he wiped off other bloodstains, but did not notice that he left real blood in the cubicle.

Jian Jing walked out of the bathroom, carefully paying attention to the walls on both sides, and finally found another drop of blood on the edge of the stairs leading downstairs.

The men's bathroom is below the women's bathroom, could it be... she turned into the men's bathroom.

There was nothing.

That's right, it was too strange for Tang Yuran to die in the men's bathroom. It was difficult for a girl to enter the men's bathroom without reason. And someone could come to the bathroom at any time, so it didn't make sense for the murderer to choose to kill here.

Where is the first crime scene?

The building is full of classrooms, and if a crime is committed in any place, a lot of blood will be left behind.

Jian Jing took a quick look and checked every classroom, but found nothing. But in the women's toilet on the second floor, some suspicious blood spots were found.

There were some coagulated blood spots around the innermost toilet.

But it is hard to say what the bloodstains in the women's toilet are, and they may not be left by Tang Yuran.

Even if it is, this may not be the first crime scene - if it is a crime of passion, it means that the other party had an appointment with Tang here or they just met, so the suspect must be a girl, but does Zuo Xin have the strength to carry her upstairs? If there was a premeditated plan, they should be waiting in the toilet on the fourth floor. No one would not go to the toilet on this floor and run down two floors to solve the problem, unless the toilet on the fourth floor was broken.

But she just checked and found no problems with the toilet on the fourth floor.

The possibility of it being outdoors is higher.

I must go back and take another look at Tang Yuran's body.

Jian Jing went back to the fourth floor, put on disposable gloves for eating fried chicken, and examined Tang Yuran's body. Her body seemed a little stiff, but because she had no forensic knowledge, she could not determine the specific time of death, and could only speculate from other traces.

Tang Yuran's hair and clothes were not wet, so she was very likely dead before the rain and was taken back upstairs by the murderer. There was some dirt on the soles of shoes and the corners of clothes, but the ground near the teaching building was all cement, and it was only in the small garden behind the building that it could be stained.

Did she meet someone there?

Wait.

Jian Jing was surprised to find that there was a faint trace of blood on the disposable gloves.

She checked again and found a more hidden wound on the back of Tang Yuran's head, with blood scabs and some fine dirt particles in the hair. Is this a fatal wound, and the knife wound on the body is a post-mortem wound?

Without knowledge, it is impossible to judge.

Jian Jing was overwhelmed and had to go back to the classroom first.

As soon as she entered the room, Zuo Xin immediately reported: "Wang Hao has walked away, look at this video." Without waiting for Jian Jing to react, she quickly fast-forwarded to 22:35, and the scene facing the teaching building appeared on the screen.

"Look here." Zuo Xin is also a mystery enthusiast, and her observations are meticulous. "There is his shadow in the lower left corner, but at 36 minutes, the shadow disappeared from here, and it never appeared again in the next few minutes."

Photographer Wang argued: "Can't I stand somewhere else? There are too many mosquitoes there."

Jian Jing did not comment, but just asked: "Did you take a picture of when it rained?"

"Yes, it started at 23:02." Zuo Xin said.

Jian Jing quickly calculated in her mind, very good, no one's suspicion was cleared.

She touched her chin and said to Photographer Wang: "Excuse me, take off your shoes so I can see."

"Why should I show you?" Photographer Wang reacted violently.

Even President Hu noticed something was wrong and asked sternly, "Why are you reacting so strongly, Old Wang?"

"If she doubts you, you will be like me," said Wang, the cameraman, coldly.

Jian Jing was considering how to persuade her when footsteps were heard outside the door. Lead Luo and Deng Dao Ju came back. The two heard the argument before they even entered the room and couldn't help asking, "What are you doing?"

"Have you found any clues?" Jian Jing asked.

Deng Daoju put a rhinestone butterfly wing on the table: "I found this in the small garden at the back. It was from Tang Yuran's earring."

Jian Jing had just examined the body and confirmed that a butterfly wing was missing from her earring: "Tang Yuran has been to the small garden at the back. Who asked her out?"

Hu and Zuo Xin looked at Wang Shexiang and said in unison: "Take off your shoes?"

Wang Shexiang's face was livid.

However, he knew very well that the more he refused at this time, the greater the suspicion. If he caused public outrage, they might hold him down and take off his shoes.

After weighing the pros and cons, Wang Shexiang chose to take off his shoes: "What can this prove?"

There were traces of mud on the soles of his shoes.

"Yes, I've been to the small garden. Shouldn't I look around for the scene?" He put his shoes back on and continued to defend himself.

Deng Daoju lowered his eyes and thought for a moment, then suddenly said, "When I went to wash my hands, I went to the toilet and saw Tang Yu Ran going to the back. Didn't you see her?"

"When?" Jian Jing asked.

"The paint was not easy to clean. I washed it for about ten minutes and then went there. The window in the toilet just faced the corner of the building, and I saw Tang Yu Ran going that way." Deng Daoju explained, "That's what I just remembered, so I pulled Luo to the back to have a look."

Luo nodded, confirming what Deng Daoju said.

President Hu analyzed: "They went there around 22:20, and you will be the next one to go out, Old Wang. Did you make an appointment to meet with Tang Yuran?"

"So what?" Unexpectedly, Photographer Wang admitted it. He said impatiently, "She and I had something to talk about. We agreed to chat in the small garden. I put the camera away and went over."

Jian Jing raised her eyebrows: "How long did we talk?"

"Two or three minutes. What we talked about was very simple." Photographer Wang said, "She must have been followed to the toilet and killed after she went back. It had nothing to do with me."

Jian Jing thought for a moment: "Then when you asked Hu to come down..."

"We had finished talking. I passed by the garden and thought there was a nice tree there, so I asked him." Photographer Wang's narration was clear and coherent. "Old Hu, when you came down, I was under the tree, right?"

President Hu nodded.

Zuo Xin said, "You two separated later, right?"

President Hu nodded again helplessly.

Zuo Xin made a "you see" gesture and said calmly: "This doesn't mean anything."

Jian Jing was the opposite of her. She felt that Wang's admission of meeting in the small garden weakened his suspicion. Although he had concealed his meeting with Tang before, considering Tang's death, this avoidance of suspicion can be understood. But if the first crime scene was the garden, Wang's admission would greatly increase suspicion.

He could have said that the mud was rubbed from somewhere else, such as before he came today. There was no need to risk admitting it.

So from this point of view, his testimony is more credible. At around 22:40, Tang Yuran was still alive. Next, President Hu, Zuo Xin, Luo and Deng Daoju left one after another. Who is most likely to be the murderer?