If the BF usually spent the night but she shooed him away that night, then she was expecting someone, Imo. So if this is the case, Imo, either that person killed her as a result of an argument, or maybe the BF came back, suspecting something was going on. In any event, I feel like she let someone in.
But...if someone she knew was coming over...not sure how to explain LE thinking he lived nearby, unless he parked car elsewhere (in case BF drove by?) or she had a special friend or ex in the neighborhood.
In my youthful single days...I remember making late-night visitors doing a long park & walk, to prevent another guy from seeing a particular car in front of my apartment. Once, the guy had to leave a different way as the other guy was parked in front of my building, watching.
Still...the little LE is saying about this case makes it even more confusing to try to get an idea if they have a suspect or not. The info about the DNA is most confusing; they say they have the evidence that will show who the killer is yet won't or can't rule out the boyfriend.
I watch a lot of true crime shows. Just this weekend, I counted eight times that Le said who they were able to rule out and why, early on. So they DO rule people out, if they can. It is easier for them to get people cleared if they can, and also makes life easier for the POI's and/or those close to victim to be officially cleared. I am not understanding why LE will not just clear the BF in plain terms. Jmo
Jmo