My theory: This is such a complicated story. I think Baron was trying to protect Jonathan when he found the notebook. He also probably had to take medicine bc he got hallucinations of Kister killing his brother. Robben is suspicious plus it would be crazy if he was the copycat bc he’s working on the case. I think they were trying to throw us off with Robert due to his backstory. He might be a perfectionist but I’m not sure if he’s the copycat. The Cicero seems to understand a lot about what’s happening w/ Jonathan so idk what’s up w/ him I still don’t trust him. It could have all been his plan + getting info from Jerome. And he did meet w/ Jon then Kister got a mysterious phone call. U never know. Also I do think maybe kister was framed/ possibly isn’t a serial killer. That suspicious phone call person[mystery person](could be a new character or someone we already know). Lastly there’s Jonathan nightmares. I don’t think those are normal I think he lost his memory. Maybe the real owner of the notebook was going after Jonathan. Kister was there (possibly saving him) and Jonathan thinks he’s the one who tried to kill him (subconsciously). And I think the Baron was also a witness that day. So 4 ppl could’ve been there at the time he fell from the cliff. Jon, Baron, Kister, and mystery person. But I think Robert was digging into what happened that day so he’s just causing trouble w/ finding out whose copycat or real killer[mystery person].
Thoughts on your theory:
I don’t exactly remember Robert being at the cliff. But he could be obsessed w/ Jon or is useful to him. I’m not completely taking him out of the suspects list. I just think the author is trying to throw us off so it’s a complete surprise. Either way if he was at the cliff he could be the copycat. But I’m not so sure that if there’s only one killer besides Kister around. It could be Robert, Robben, Cicero(doubtful atm), a mystery phone person. I’m completely ruling out Baron if he turns out to have killed to save his brother which was what I originally thought at the beginning. I’m going to be pissed. (He could have done this in order to kill Kister/ anyone who is after his brother.) also wanted to know about the name thing too.
I feel like Robert is going to be the copycat, tbh. The weird thing about the painting and needing things to be perfect, the facts that he already has this weird possessive vendetta against Jonathan, and the fact that Cicero warned against him AND he has money so that could have been the reason baron is on the run... but if I remember right, only Robert and Baron were there when Jonathan fell off the cliff? Maybe Robert pushed him? Idk so many plot point haven’t been covered yet! Honestly though, I trust Cicero and Baron the most— Cicero seems like he has no motive and Baron seems like he would never hurt Jonathan. Also, anyone else catch how the last murder victim’s last name was MARCH and Jonathan’s last name is APRIL?? You gotta wonder what the theme is and if we’ll get anymore context from previous victims— or if it was just because the author thought it would be fun lol