Trapped with psycho

Trick

I and Jimin continued my brother's investigation , that is when we found all the persons who died except Monica and Kai were the ones who bullied or hurt me , but Karen , I don't know , she stands out . Rest all hurt me in school , this proves he is obsessed . We kinda are sure it is Jungkook because when we saw the call list of all the dead students, Jungkook was in all the call list . But Jimin is a bit relaxed once he finds out it is Jungkook . Of course , they were friends, but ...

I can't believe Jungkook did all this just because they hurt me . I was still processing all what happened when suddenly we had a knock on the door , Jimin checked no one , suddenly current went off , we used our phone flashlight, someone is banging at the door , Jimin immediately closed the window , but too late , we felt something come in , I could hear a dragging noise too , I guess Axe or something, before I could shout Jimin pulled me into a nearby closet . We heard a creepy noise "Don't hide from me , I am no harm, Jimin ah , am I not your best friend, I didn't kill Tae, believe me" , I felt Jimin getting frustrated. But he slowly opened the door , he pulled me  into something, it was a under ground passsage , he said "when my parents forced me here , I escaped through this ," it was emergency apartment fire escape stair , I don't know how we reached there but we were there , but I could feel Jungkook not far behind , suddenly he threw something hard , I and Jimin rolled down while he said "trust me , I love you guys" as soon as he came near me , I saw his doe eye , I got scared but suddenly we heard a gun shot , the police arrived and shot his leg . I sighed in relief .he didn't even shout but he was bleeding.

He has been taken to the mental asylum, I asked Jimin about their friendship, he said " we were good friends but he got jealous over a girl and killed Taehyung but even though he denied , there were witnesses" , I was so sad , I don't know about taehyung but it seems he was liked more by Jimin . The doctor said we can meet him in the mental asylum, so I went . I didn't go in but heard his confession "I didn't kill Taehyung, she did it because he knew her secret , I was the only who witnessed it  but no one trusted me , so I killed everyone who doesn't trust me , but I will never kill Jimin", seeing him talk like that made me cry but he killed my brother , Monica , Karen.

I and Jimin went to Jungkook's house , there were many creepy things , it had my pictures, Jimin's and Taehyung's , I went through random stuffs , when I tripped and fell, it was a wooden box , I opened in , there was Karen's phone , I opened it and went through many chats of us , but suddenly I saw a chat group name "tricksters" , all the person who died were in that group including Karen , that is when I came to know the truth about Karen , she wasn't really my friend she wanted to hurt me , all of them , Jungkook was in the group too , he named himself Jimin , in That group , so he killed them all because they were gonna hurt me. 

Chats 

Selin : Karen , spike her drink 

Karen : but that bish won't come to parties 

Lia : spike her water 

Milan : after that bring her to me , I will take care 

Karen : can't wait ....

Jimin (actually Jungkook) : why not later week , during our school festival , she would be embarrassed infront of whole school.

Karen : clever Jimin.

Reality:

So his plan was to kill everyone before the school festival which has been postponed,I can not believe Karen actually did this to me , I cried , Jimin comforted me , I thought after all , my bully Jimin,  was not my only bully , there were people who were ready to kill my reputation and ruin my entire life , and the person whom I thought my BEST FRIEND was the lead role in this .

Jungkook did do something great but ... killing is too much. Now will he kill me or not ?

I didn't trust him . Why did he kill taehyung? Who is the she?