After hearing K’s sister describe her as the girl with no past problems or enemies (“everyone’s daughter, everyone’s friend”) and thinking more about the extremely gruesome crime scene, it’s my opinion that this crime was committed by one individual, and it was someone they knew who was on the periphery of their social orbit. I say all of that for these reasons:
1) It is quite often the sweetest and almost too perfect people who can inspire the most anger, resentment, and jealousy among others. So if K really was that beautiful inside and out, it’s entirely possible there were girls who were jealous of her and just pretended to be her friend as well as guys who resented her for not returning their affection or paying them enough attention. There was a guy like that in my high school- best athlete in the school, model looks, and even an honor student, and literally the most humble and kind guy ever. He shouldn’t have had a single enemy, but he was secretly resented by so many, including some of the guys who hung out with him.
2) It is highly unlikely the killings were an unplanned crime that happened during the commission of a burglary or assault. If someone is robbing the house and suddenly is caught by a tenant, it is very unlikely that criminal would stick around and go room to room savagely eviscerating everyone there, leaving behind such a bloodbath of overkill. Burglars or even rapists like to get in, commit their crimes, and then get out.
3) I’m no expert in burglary, but I would think that a very large knife such as the one police are looking for wouldn’t be in your typical burglar’s toolkit. Feels like that would only get in the way. That type of knife would almost certainly be brought into the home of someone else for one reason alone- to commit a large amount of violence. To kill.
4) And while it has happened before, it is absolutely VERY rare for a complete stranger to break in to a house full of people in the middle of the night and slaughter them so brutally without any other motive. Drifters break in to houses to steal. Rapists and even most serial killers break in and kill while also committing sexual assaults, with usually just 1 victim. The psychopathy required to break into a house in the middle of the night and then so savagely and repeatedly stab and slash that many complete strangers for no reasons other than “for fun” is off the charts and (thankfully) not present in most people. That’s Manson Family level stuff.
No, to me, this crime points towards a motive involving jealousy, resentment, and pent-up anger likely built up over months or even years towards one or maybe two of the victims. I’m guessing it’s going to be someone who had interacted with at least one of the victims on multiple occasions. Maybe it was a frequent customer of the restaurant where they worked and the killer mistook kindness for affection and then snapped when he found out he had no chance for love. Or maybe it was someone who was a friend of a friend who attended some of their parties and for whatever reason felt rejected by the girls and as though he would never really be a true part of their social circle. Maybe it was a neighbor or a classmate who got friend-zoned and after a while couldn’t take it anymore. Or maybe even something as simple as a guy who bought them drinks one night and became enraged when they shot him down. I think it will end up being someone who was known to the girls (and maybe even the surviving girls) who they never thought of as anything other than a casual friend or acquaintance and never considered a threat. Thus, they never would have alerted family or friends to his presence in their lives because he hid his hatred well. And as cliche as it sounds, I’m betting there was a trigger event, either in his own personal life, or perhaps even in his interactions with one or more of the girls, which made him snap and decide to kill that night.
The killing was extremely personal. It was filled with rage. It was up close and while they slept. It was overkill, to say the least. It was someone who had met them before in some capacity. MOO.