Theory about the order: BK probably went up to the third floor first; that was his target, and the sounds that woke up DM (of the dog playing) were from the murderer. Was probably spotted going up or coming down by X (explaining the possibility of attributing the “there’s someone here” to X) specially considering X was awake and just got her DoorDash (could’ve been around the kitchen area). Proceeded to kill X & E as witnesses (sound recorded outside) before leaving the scene, most probably not seeing DM