I think the opposite, one killer is probably the most realistic scenario. You just have to look at what KIND of murder this was. There's no robbery, no money, no drugs. Personal motive. Think of like an OJ, rolling up to Nicole Brown's house, just livid with rage and probably high. It's not an easy "hey man come with me to my old girlfriends house, at 3:00 AM, I'm going to teach her a lesson"
it just doesn't sound like there was much of a struggle, or ordeal. Like hours of torture or abuse. What I think is possible is a kind of scenario, where something gets out of hand, between TWO people, and goes too far, and the killer commits the crime FIRST to shut up the victim, (realizing the consequences for lets say punching one of the women in anger) and the others as witnesses, or because the other would know, for instance who one of the girls would call to hook up with at 3:00 AM. Or who would show up without calling. But, then we don't know what's come up on the phones.
In sexually motivated crimes, there is usually mutiliation to the breasts, vaginal areas.
If you had rape/torture, there have been instances where two men, who usually meet in prison, participate in these kinds of sexually motivated killings for pleasure. If you had robbery, maybe, like if it was some trap shyt, and two guys go in to steal some work, and end up killing 3 people in the home.
