I understand that cleaning ALL of the blood would have been very hard, but he probably didn't spend several days "cleaning" the basement, since her blood was found there in several places and on his car. He tried, but I doubt this guy was cleaning for days. I'm guessing he cleaned the vast majority of the evidence so the girlfriend wouldn't really notice it, but he clearly didn't do that great of a job, since LE found blood in several spots the very first time they searched the house.
Isn't that his house? You can't kicked someone out of their own house lol. She could've left, yes, absolutely. At this time, I'm inclined to believe that she didn't participate in this horrific murder, I'm not sure if she eventually started realizing something was wrong. I mean, we have seen time and time again, where families are presented with overwhelming evidence that a family member committed a crime and they don't believe it, it doesn't surprise me. Some people will just deny, deny, deny, some just refuse to believe or even question things, some will know that yeah, their family member probably did it but will still deny it and keep that to themselves. Nothing surprises me anymore.