Summarized from Reddit
>\*allegedly\* (in no way my opinion, simply a summary and translation) 2 frat boys in SX with the same first name did it (some rumor- meaning discussed to a lessor extent or debated- they're in a sexual relationship). E and X got in a fight with frat boy 1 (weak rumor that they caught FB 1&2 having sex that night). E had a reputation for sh\*t talking and referenced FB 1's roid testicles. There was history of frat boy 1 not liking M because he wanted to get with her and thought her boyfriend was ugly. Frat boy 2's bedroom looked out on 1122 and they waited for the lights to go out. Frat boy 1 is an athlete and roid bro and knife hobbiest, he did it. frat boy 2 was on lookout. (some rumor there was a girl who helped watch or knew they were doing it) They left their phones on a youtube video at the SX house and are each other's alibis. Supposedly have already been interviewed and cleared because their DNA isn't in CODIS. K was victim of circumstance. (some rumor regarding FB 2's SM response to supposed injuries claiming they're incorrect. I believe those SM posts are deleted.) Took 19 minutes total and supposedly they were bragging about it after. Some indication of intent prior as they had discussed how to get away with murder (i.e. use electrician gloves and knife- quietest, put on baggy clothes after to cover blood and get out faster). It seemed like they were waiting for a reason and were presented with one. They both wiped their SM immediately after and were not active for 2 weeks. Frat boy 1 family is professional cleaner, frat boy 2 mom paralegal so they knew what not to do when questioned. There was some rumor that one of the J BFs knows all of this and is keeping hush and "playing the grieving boyfriend".
Regarding the surviving roommates, as far as I can translate there was no beef and that's why they survived.
This is "***** substantiated" by a few different users and allegedly a lot of this is well known within the frat. SX has a shady history going back to the 90s. \*allegedly\*