who murdered park jihoon

interview- park woojin

i: what kind of relationship did you have with park jihoon?
pwj: we were good friends, but recently we've grown apart as it's been very tense between us.
i: could you elaborate on that?
pwj: jihoon and i are in the same grade, and we attend the same school. we're both pretty good students, but we're also both pretty competitive. jihoon had been top of our class for months, while i ranked #2. just recently, about two weeks before he was murdered, the class ranks were posted and he had dropped to #3 while i was #1. he didn't take that too well, and both of us being very competitive just made it worse. when i went out to hang with friends, he would text me things like, "what are you doing out? shouldn't you be studying? well, i'm studying! if you're going to come to the dorm with your noisy friends, i'll cut your throat for sure." i would show you the text messages, but jihoon threw my phone out of the window while we were arguing about grades. and unfortunately, his phone is shattered too.
i: what were you doing the night of jihoon's murder?
pwj: we had practice until 1 AM and all arrived at the dorm around 1:15 AM. i just remember taking a shower, brushing my teeth, and blacking out in my bed. jihoon usually sleeps in my room, along with kuanlin, minhyun and jaehwan, but that night, i remember he insisted on staying up to study. he didn't want to disturb us by keeping the light on so he slept on the couch in the living room. i heard a scream at 5:47 AM in the living room, i suppose that was jihoon.
i: did you notice anything strange that night?
pwj: he's been acting really strange with me ever since the class ranks changed, but that's just in general. i do remember something odd though. when i woke up to the scream, everyone in my room was still present except kuanlin was gone, and the door was wide open.
i: who do you think murdered jihoon?
pwj: i think it was kuanlin or jaehwan. kuanlin was out of bed when i heard the scream, so he's either a really good witness to the murder or the murderer. and for jaehwan, i remember he owed jihoon a lot of money. one time when he was drunk, he spam texted me about how he would never be able to pay his debt to jihoon and how he was screwed for life. you can ask him for those text messages, i don't have them.