The letter points the finger at the fridge because that implies a master key was used during the crime (i.e. makes the apartment owners look liable for security issues).
But back to the downstairs fridge. I think using the victim's fridge make more sense. Could space have been an issue? Then both would be used.
I don't think disposing of the torso was a problem size wise (unless the plan was to bury it in the woods, and yes that would require a lot of work and possibly lead to procrastination). The torso in the trash can has always bothered me about this case, I have always wondered WHY???
I am fairly convinced now the reason was the odor. If in fact (yes, this is rumor) the torso was cut in half then that could have caused really rapid decomposition. If the intestines are ruptured the bacteria that is released speeds up the decomp process a whole lot. Now a hunter would know that (or someone that watches to many real crime shows), but if if the "real killer" wasn't a hunter they may not have known that. Did he store the torso thinking it would be fine for a couple of days and then suddenly realize it wasn't fine when he had to move it? I think that is exactly what happened.
If that is in fact what happened and it WAS stored in the downstairs fridge, then why on earth did it take them week's to realize the downstairs fridge was involved? Surely the cadaver dogs would have freaked out over that fridge immediately! If they knew it was involved that would be one of the best pieces of possible evidence, why let it sit in the complex for TWO WEEKS before admitting it as evidence?
Since they didn't use cadaver dogs on any of the other apartments at the complex (I believe that is the case, isn't it?) then it could have been stored in ANOTHER fridge that the dogs never checked!
Picture below as fridge was removed in mid July. Note the guy moving it is NOT wearing gloves....I don't see any finger print dust either. They were trapsing in and out of all 3 apartments for weeks, if the evidence was NOT protected who's to say they didn't track a hair in from one apartment to another "accidentally"?