"Director, it's not good. Something happened again, something happened again". A young police officer, with one hand against the wooden door of the office, hunched over and panting.

"Tell me what's wrong." Zhou Qingmin didn't care to blame him for coming in without knocking, his brows furrowed, and a bad premonition suddenly rose. I looked at my watch, and it was 11:10 p.m.

"A female head of household in Building 506, Building 8, Dongsheng Community, also died."

"Notify the others and go to the scene to check immediately", Zhou Qingmin didn't have time to ask about others, put on his clothes and walked quickly to the door, and after a while, the roar of the car started sounded.

"Director, deceased, name: Yu Ting, 28 years old, like the two previous deceased, died of suffocation in the secret room, and the time of death should have been between 8 pm and 11 pm. There were no other injuries on the body. Dressed neatly, no sexual assault. The deceased should have been in a coma before he died, and the scene had been dealt with by the murderer, the home had been checked, and all valuable items were there, so the possibility of robbery could basically be ruled out. And the modus operandi is almost identical to the previous two cases, so I conclude that all three cases must have been committed by the same person." Li Yu squatted next to the deceased and said loudly, and his expression became more and more serious when he said it.

Who reported the crime?

Ms. Li, a neighbor, confessed that she and the deceased had made an appointment to play mahjong together at 8 p.m., but at 8 p.m., Ms. Li went to the deceased's door and knocked on the door, but no one answered. Calls were not answered. It wasn't until 10 p.m. that Ms. Li came back from downstairs and saw that the lights in the deceased's house were on, so she wanted to say hello. The result is still the same. So she called the police. There was nothing suspicious about Ms. Li and there was no motive for the killing." Wang Yi came in from outside the door and said, apparently he had just learned the situation from Ms. Li.

"Carefully collect the evidence at the scene, this must be a homicide." At this moment, if Zhou Qingmin can't conclude that he killed these three cases, then he is not worthy of being the director.

"Hey, this finger mark here is a little weird, but it's not obvious." Li Yu said with a frown while gesturing the deceased's neck with his hand.

"Yes. This finger mark is a bit strange. Wang Yi also leaned over to take a look. It's like a person has an extra finger on his five fingers, but it's not obvious, could it be that the murderer is holding something?"

After speaking, he couldn't think of a reason, Wang Yi walked to the window, pulled up the lock on the window, and gently pushed it out, and the window here was also locked. The door is also anti-locked. How the hell did this murderer get out? This room is sealed except for the doors and windows.

"Wang Yi, let's go, the scene has been investigated. Let's go back to the police station first. After a while, Zhou Yu walked up to Wang Yi and whispered. Seeing that Wang Yi seemed to be thinking about something, he took Wang Yi's hand and wanted to go outside, but as soon as he touched Wang Yi's hand, his face couldn't help but flush, and he drank lightly. "Let's go". Thankfully he didn't see it. Zhou Yu was secretly happy in his heart.

Back at the police station, everyone's expressions were even heavier, and now no one would be stupid enough to say that it was a suicide. Could it be that this month is too good? Everyone is rushing to kill themselves? There is no reason to be able to say in the past. Even Wang Gang and Liao Zhixiong didn't want to touch this nail. But on second thought, this murderer is too arrogant. The policeman was still investigating the first two cases, and less than a day later, he ran out and killed another one. Is this too much hatred or a provocation to the incompetence of the police department? If it is hatred, then what kind of hatred makes the murderer kill three people in a row?

"Wang Yi, why don't you wash your hands when your hands are so dirty"? Zhou Yu said softly as he passed by Wang Yi, wiping his hands with a tissue. Apparently just washed hands.

"Wash your hands? Why wash your hands"? I didn't touch the corpse just now. Wang Yi also had a question.

"Then I just took your hand and my hand is dirty. You see, I just went to wash it." Zhou Yu said and compared Wang Yi's little hands that were whiter and tenderer than himself.

Boom, isn't it? Yes, it must be.

"Director, I'll go out and come back soon." Wang Yi couldn't help but look at his hand, and the index finger of his right hand was indeed a little dirty. But where did it come from? And like rust. By the way, it is embroidered on the window lock of the window, under normal circumstances, the room is inhabited, and the window is often opened and closed, even if there is rust on the window lock, it will not get your hands dirty. So what will happen to you? Wang Yi couldn't help it anymore when he thought of this, he had to confirm it, maybe it was really what he thought. If that's the case. Then the murder in this secret room can be done very simply.

Sure enough, Wang Yi carefully observed the places of death of the three deceased, and found a small scratch on the window, which really can't be found if you don't look carefully, if the murderer kills someone, he goes out of the window, and then ties a small fishing wire to the window lock of the window, and so that the person who fixes the same person pulls the silk line outside the window, so that the window lock will fall, and the window looks like it is locked inside. After checking the window, Wang Yi came downstairs, if the murderer came down from the window, then there must be footprints on the lawn downstairs.

Everything is as Wang Yi guessed, after the murderer, after the murder, he processed the traces of the scene, got out of the house in this way, and left footprints on the lawn in the process of escaping from the window, although the footprints are not very clear, but through Wang Yi's judgment, the murderer should be a man with a height of about 175, and his body should be considered thin. First, the length of the grass mark is about 42. Second, the grass marks are very shallow, which shows that the murderer weighed no more than 120 pounds, and for a man with a height of 175, a weight of less than 120 pounds is already considered thin.

As far as the current situation is concerned, the murderer is a vendetta, so for three women in their 20s, what kind of hatred will make him kill the killer? Or is there some unknowable story between them. Right. Now is the time to start investigating this aspect. Thinking of this, Wang Yi rushed back to the police station non-stop and told everyone about his findings. Then, under the direction of the director, a more detailed investigation into the past of the three deceased persons began.

However, they seem to have missed another important point, is the murderer's motive for killing the same for the three deceased? If it's the same, then the murderer has a feud with 3 people at the same time, then it should be easy to find out, if not then why? Or is it just a feud with one person, and after killing the deceased, the latter two discover the password? Anyway, we now have a general direction.