He did kill his father it was in one of the chapters
Yall really just be looking at the pictures
I really don't know what to think cus in the first chapter, there was clear dialogue saying there were going to rob/kill whoever they find (OK I can't remember but it's there for viewing in the first few chaps). So I think maybe, because Jinwoo is weird at night sometimes, maybe his father was a bad dude and wanted him gone. He was just faking to the main nice DID personality. I DUNNO MAN IM WITHHOLDING JUDGEMENT
I feel like its really guwon who killed teach's father the author just give us mental gymnastics on believing its teach who killed his own father just because hes an unreliable narrator haha imo