This case reminds me a lot of the famous Springfield Three case. There are obvious differences (mom, daughter, and friend as victims vs. four college friends, bodies never found vs. bodies at crime scene, etc.). But I guess it’s just the whole friends possibly being followed home from a night out angle, the whole “who was the intended target?” question, the “how did nobody else hear anything?” question, and the question of how the killer gained access without signs of forced entry that make me compare the two.
As someone who did a fair share of partying and going out late in college, not to mention someone who lived in a house filled with roommates, I can easily see how 2 people in the house didn’t hear anything happening. Or, even more possibly, they heard some commotion coming from upstairs, but maybe it wasn’t the loud chaos we all imagine and the downstairs girls were used to hearing footsteps, doors slamming, random “thuds”, etc. So they could have heard some noises and if there weren’t any loud screams, they might have just thought it was their roommates coming home from a night of partying and being loud.
And I can think of five reasons why the downstairs roommates weren’t harmed: a) killer didn’t know they were there, b) killer couldn’t get into their rooms because they were locked, c) killer felt rushed, spooked, or short on time for some reason after killing the first four and hurried out, d) killer had no reason to kill them and only killed the other four for a specific reason. The fifth reason is fairly obvious but I will just leave it unstated as there’s a very good chance it’s not the reason anyway.
I do think, though, that the police have a pretty good idea who committed these murders, or at least have a general idea. The reason I say that is because of the contradicting “targeted attack vs. no threat/still a threat” statements made. Police and others in the know generally don’t just make statements about there being no threat to the public without some kind of idea of who did it. I think they have a very specific person or persons, or at least a specific scenario in mind and can say it was a targeted killing with LIKELY no threat to the community (due to the perceived motive). But because this person or persons is/are still at large or not under arrest yet, they might be dangerous enough to commit another killing if cornered or uncovered. Just MOO.