The first two suspects that pop to mind are the inexplicably absent Lakota and Jenna. Now, I might be wrong, not having read the earlier stories in this series.* But, in most conventional "whodunits," that's precisely what the author does. He or she initially misdirects the reader with a _plethora_ of mysterious-acting suspects, with various and sundry grudges against the killer and/or framed protagonist.

*Not yet, anyway.