DW, it's safe to say that Baron only becomes suspicious cuz he's trying to do it discreetly to protect Jonathan.. from the beginning, it's pretty obvious, he found out about Kister's diary thru his investigation, read Jonatan April's name written im the back, rendering to think he might become the target..so baron did what he did to conceal that info from anyone...as not to make Jonathan panics...besides he needed to collect more evidence before he took any real action cuz apparently there's another 'Kister' out there, and those graphic murder scenes might not be of real Kister's doing..
That's my 2cents, i didn't read raws so eventho many readers still suspicious about Baron i nvr thought so, we still didn't know why April become the MC here and may be the target of killing, what's so special about him that can give motive for murder...I get suspicious about anyone here but Baron and Jerome, Baron had the most chances to hurt April if he wants, the fact that nothing happened means Baron isn't the one.. he might even be on the same page with Kister actually, protecting Jonathan
lol he didn't
All this hints lead us to get conclusion, Baron did the last case to protect Jonathan.
But I don't want to believe it because everyone in this story is suspicious.