Alzheimer is quite deteriorating but it's really harder on the care givers than on the patients since not all present pain, they just have no consciousness or remembering of who they are or how to do things, in the very worst like this mentioned they cant feed themselves or care for themselves, this does NOT mean however that they may have small periods of time which they have lucidity, not to remember things but to be aware of themselves as beings and their surroundings...... if the woman presented no pain then there was no need to kill her other than his desperation of seeing her like that because he didnt like it, which is no grounds for murder....