I think it's really interesting that of the criminal profilers interviewed on Inside Edition, the 2 males seemed to both think the perpetrator knew them and that this is more of a personal/revenge crime and the 2 females seemed to both think there's more likelihood that it's someone unknown to the victims who has practiced/done this type of killing before.
Experienced crime experts are weighing in on the murder of four University of Idaho students. Dr. Casey Jordan suggests the killer was gradually building up to committing the monstrous deed.
www.insideedition.com
I just think it's interesting how their theories broke down by gender.
Personally, I think with the amount of time that's passed, it's less likely the perp was connected to the victims socially. I feel like LE would have some kind of strong leads on person(s) of interest or actual suspect(s) by now.