Except why does any of this make sense? Just because it can't be pinned on anyone, it has to be them? Why should it be a slam dunk conviction simply by process

Except why does any of this make sense? Just because it can't be pinned on anyone, it has to be them? Why should it be a slam dunk conviction simply by process of elimination? We don't know the witness or even the victim, by way of this article. Who were they?