I really hate to sound like I"m blaming victims and I know there must be a reason but why do people think the roommates waited so many hours before calling 911??
Well, initially I had actually hoped that they called earlier, that LE made a small appearance in non-official cars after it was clear they were deceased (could this explain photos taken by BF?), and immediately went into let's send no information out, stalling the 911 call from record. They would have to be quick on their feet for this kind of thinking. Then, they could sit and watch if the murder came back.
Maybe it's wishful thinking, but it is possible (obviously this conflicts with what's reported). JMOO