Then why not just kill them?
There are multiple cases of families or groups of women being attacked in their own homes that turn out to be robberies or sexual assaults, or both! In the vast majority of those cases, the crime is almost always limited to the household. There's no need to dump the bodies, only the need to dispose of any incriminating evidence. Apparently there were no signs of foul play or robbery, which indicates that the abduction was the only thing that took place at the house. This is interesting, because if it was sexually motivated it means we're dealing with someone who wanted the women for a prolonged period of time. Someone not dissimilar to Leonard Lake, who abducted women and used them as sex slaves until they were expendable. However, Lake's victims were lured to his cabin out in the country under false pretenses, not quite the same deal here. It's rare enough for one woman to be taken from her home, but kidnapping three adult women in the middle of a residential area is almost unheard of, hence the extraordinary nature of his case.