What sort of person is willing to murder a close relative and harvest their body for organs? I've never heard of that happening with anybody and an identical t

What sort of person is willing to murder a close relative and harvest their body for organs? I've never heard of that happening with anybody and an identical twin, even one raised apart from them. I think this is even less likely in the cloning for organs scenario given that you'd have to bring someone into the world and raise them from birth intending to murder them later. Though of course if you can clone just a liver, say, that's a different issue and that might very well be the main source of clonings in the future.