Its complicated, it had to be someone that knew all 4, one thing to attack two and leave, but then go to another floor in the building and kill them as well. Had to be someone that was jealous, ostracized by all four of the victims.
I don't think a pissed off ex could pull off something like this. Seems like a complete psychopath serial killer that might have killed before or a professional hitman..Someone with ice water in their veins for sure...
I don't see how a normal person who never killed before could snap so bad that they would use a medieval weapon like a knife instead of a gun...A normal person that just snapped would probably want to get in there, do the dirty deed and get out quickly, with as little trouble as possible, and I wouldn't think they would want to take the risk of using a knife when they could possibly get over powered or not know where to hit a person with a knife and possibly leave one of them alive by mistake.
If it was as simple as it being an ex friend/ boyfriend, etc, they'd probably be in custody already. This is like some MS13 gang crap or something. Stupid college kids messed with the wrong drug dealer or some crap.
