What is the potential the use of the knife was chosen for a ritual purposes* or for a symbolic reason? Or, what if the choice of the weapon was for silence, where the intention was a sub-set of the victims, and success would require silence? But, then the reality of the action expanded the victim set to the total four victims?I wanted to piggyback off of this reply because you made great points about lowering the risk of being caught.
My question is, if all of that type of planning happened, why use one of the messiest/riskiest weapon choices out there?
IMO: because the perp didn’t care. They just got lucky.
MOO
Ritual doesn't always mean a formal rite performed for a diety. It could be for a personal belief structure that is internal to the criminal actor.