Just a thought and maybe this has been covered, but I think there's no way this was someone that they knew in Greek life or in their circles at college. Like with a lot of mass shootings, people always know *something* about the perp's propensity for violence. Usually family, but living on a college campus or in Greek housing/dorms, either people know exactly who it is (based on weird behavior, threats, etc.) and they are being forced to keep quiet because LE is well aware and not releasing anything yet so they can build an airtight case, or it was someone fairly far removed from those circles. Because you know how quickly things travel in college gossip wise (and I was in college pre-Instagram and tik tok.)
Related to that, it's been interesting to me that members of Greek life and friends of the victims haven't really spoken about this case to media, other than early on. I imagine there is some level of being told not to do that by LE so as not to compromise the investigation, but to what extent? Given the vast amount of interviews LE has claimed to have done, no one has blabbed about what they were asked? I'm sure there are legal reasons, but it's just interesting to me given the amount of social media interest into the case that there haven't been more leaks along those lines, even if anonymous.
The flip side of that, and my gut to some extent, is that it's a older local, maybe a neighbor or a patron of Corner Club, or an isolated grad student, or a young unsuccessful alum or former student athlete who hasn't quite moved on from college life and is resentful/has rage. Maybe they somehow got into a house party at the victims' place in the past, and/or developed some kind of obsession with one or more of the victims through social media, etc. and that's how they had some level of familiarity with their schedules and the layout of the home. Close enough for the crime to be personal to the perp, but not personal to the victims.
MOO