Joe Schmoe was six years old when he killed his best friend; it wasn't his fault, it was just the way that he was made...

Joe was born with an auto-telepathic telekinetic feedback ability - he has the ability to unconsciously kill anyone who has thoughts of killing him. It doesn't matter if those thoughts are intended to be carried out - "it's the thought that counts" (to re-use a phrase). If someone has an idle though that the world would be better off without Joe being alive, then they die.

As a young adult, Joe is eventually incarcerated in prison, in solitary confinement. But he's still killing - everyone who benevolently wishes to end his solitary suffering, the relatives of those that he's inadvertently taken from their families.

How can we end this cycle of pain and suffering?

EDIT: Burki raised the question of suicide. While this might be an elegant idea, it bypasses other creative ideas. For the sake of the story, let's say that this ability is borne of self-preservation and suicide is not an option here (sorry).