[Boogieman]

Well, you can’t just kill someone and take their heart out and then show up at a hospital with it and say “I found a donor!”

I suppose you might find some shady doctor somewhere who might not worry about the provenance of an organ, but it’s not likely a shady doctor would be skilled enough to do a heart transplant. Plus there is the fact that a donor must be alive when the organ is removed. An organ from a dead person is useless for transplants.

[adorno]

Well, you can’t just kill someone and take their heart out and then show up at a hospital with it and say “I found a donor!”

You don't think there are any shady doctors out there? Perhaps it was the killer himself that was a doctor.

Also, don't you think there could be an underground trade of organs, taken legally and illegally? And, a victim's body could have been kept 'alive' long enough for the organs to be viable, and then the body disposed of in the forest?

Why remove all parts of the body that could lead to identification of the body, if it was just going to be a murder and nobody could be id'd as the killer?