I still don't think that blood is related to the crime. Meaning, she could have lost a few drops of blood at any time, with her elderly skin being so thin and all. It's entirely possible the police only mentioned the blood because the journalist, BE, went up to the front door, saw the blood, and reported on it. That should have never happened. LE should have never let anyone near that house. Because we know the blood is NG's, and if LE thinks it was deposited there during the crime, then BE basically tampered (unknowingly) with the crime scene.
IMO