So, if drugs are involved, three deaths as a result can only stem from a previous and darker issue that no one has certain news about. Would it be necessary to investigate people who formed part of these three women's lives in a way or another and who, until now, have never been looked into?
Besides, drug criminals only act with this violence in case of treachery, and always obeying to a cartel. This is a must in these groups. Once betrayed, they never warn but destroy, so as to exemplify those nearby the "unfaithful ones" about the consequences of disloyalty. I do not believe it possible two adolescents could have gone so far with these fearsome groups. Therefore, the hint of the behaviour the criminals took revenge on, has to necessarily been found in the adult world.