I see your point BWM, but there are always two sides(sometimes more than two sides) in a debate.
I have watched a family member lapse into a living death through dementia accompanied by severe arthritic disability. The result was beyond description. Euthanasia would have been a blessed relief, but would have resulted in criminal charges.
There is no doubt that in the future such actions to relieve pain and suffering will be brought forward, but is there any difference between physical pain and the psychological suffering of people like Brady who have to live with what they have done.
If they are genuinely unaffected by their crimes they do not deserve a place in any sort of society, they are worse than the beasts which we slaughter daily....without a thought.