.....3 young pretty woman, one guy,,,living in same house....supposedly one guy is in a relationship with one of the young woman .. polyamory gone wrong? Maybe killer was crazy incel person who got sexually shunned (term: sexiled) by some in the group of victims...drugs, alcohol, dare, killer was outed?, killer wanted newer iPhone which was owned by one of the victims?, Slenderman,
I would assume the girls lived in thier sorority house. Same with the guy in his frat house, unless seniors are allowed to live out the the sorority/fraternity.