1) Rigor mortis - the stiffening of the muscles after death - and liver mortis, the pooling of blood in the lower extremities. I understand the basic concepts here, but how long do the effects last? Various sources have stated that the muscles "relax" after 36 hours, but how much do they relax? In Unbreakable, Bruce Willis unties a dead woman's hands from above her head, and they fall to her sides quite easily. Is this possible when rigor mortis is in full swing? Is it possible afterwards? As for liver mortis - will the reddening of the skin still be noticable within 24 hours? 36? Afterwards? [We're assuming the body is not moved or tampered with in any way from the time of death onward.]
2) The smell of death. If a room is kept relatively cool, how noticable will the smell be in 12 hours? 24? 36? How cold would the room have to be to make a difference? It's obviously not going to be meat-locker cold, especially because this takes place in the summer - however, the killer has air conditioning and purposely turns it up full-blast. Would this be enough to delay decomposition at all? [Basically, he knows the heroes are onto him and he wants to leave them a particularly unsettling calling-card. It's in his best interests to make sure the corpse stays intact for as long as possible after she has died - he leaves her alone with no food or water, so she dies within a few days of thirst.]
I am pretty flexible as to the amount of time that passes between the death and the discovery; I just want to make sure all the elements add up to make sense.