IMOO, these horrific murders of K, M, X, and E -- young college students stabbed to death seemingly "out of nowhere" (without an obvious motive initially) -- remind me of these other murders:
Mollie Tibbets
Farm worker found guilty of killing University of Iowa student Mollie Tibbetts | CNN
The killer lived in the same small town where the victim was visiting back home on a break from college, and
stalked the victim from afar (they were not known to eachother directly), followed by the killer swooping in when an opportunity presented itself -- the victim was housesitting alone while her boyfriend and housemates were out of town, she went for a run on a country road, and was abducted and then viciously stabbed to death at another location.
Kelsey Annese & Matthew Hutchinson
Murder-suicide in New York college town leaves 3 dead, police say | CNN
The killer was a long term boyfriend / person known to one of the victims (she had recently broken up with him) (they were intimately known to eachother), followed by the killer sneaking into her house in the middle of the night while she was asleep with a male friend in the same room -- this also happened in off campus housing with housemates on other floors of the house that heard nothing when the killer viciously stabbed them to death "in their sleep/in bed", then turned the knife on himself.
In both of these murders, the killer had a motive that was unclear at the time they stabbed the victims (college students) to death >> when they were alone and/or sleeping << which gave them a huge tactical advantage.
In Mollie's case, IIRC it took LE over a month to identify her killer (surveillance video and her fitbit/phone data were important) and he was later convicted.
In Annalese & Matthew's cases, IIRC the killer called a family member right after stabbing them and admitted to "harming her" (his ex girlfriend) and then killed himself, however it still took over a month for LE to confirm the suspect and motive and designate it a murder-suicide, and he only told one person the week before that he was "feeling low" about the breakup.
In K, M, X & E's cases, with such a stealthy approach to murdering 4 people in the middle of the night with possible multiple motives and/or targets, LE is sifting through an enormous amount of data and I'm confident they will identify the murderer(s) and bring them to justice ASAIHP (as soon as is humanly possible)! MOO!