OK, something just crossed my mind . . . possibly really dumb (won't be the first time) . . .
Just for a minute . . . wonder if the assailant did not know the building and the laundry room well. Assailant kills Leah. For whatever reason, is concerned about the condition in which she is left. Maybe it is the nature of the injury, maybe considering how to remove body to dump somewhere. Killer hurriedly looks around, maybe opening cabinets/lockers looking for something that would help, finding the storage space. Spots a plastic bag somewhere.
MountainMama's post about someone stalking Leah got me thinking. I guess the big flaw is, why hide the body at all? But I just got to wondering if the manner of hiding it could have been decided quickly, after the crime.
But even with someone who knew Leah and the building well, I still come back to the question of "why hide the body at all?" How it was hidden, where it was hidden, puzzle me far less than why?