Maybe I misunderstood what happened. It sounds like they had 4 children, 3 of whom were disabled, and then the German state caught on and punished them? If so, this seems like callous enough behaviour to me that a strong form of retribution makes sense as a deterrent just as it would for crimes like manslaughter, even if we didn’t have reason to think they’d be repeated by the individual.
Maybe I misunderstood what happened. It sounds like they had 4 children, 3 of whom were disabled, and then the German state caught on and punished them? If so, this seems like callous enough behaviour to me that a strong form of retribution makes sense as a deterrent just as it would for crimes like manslaughter, even if we didn’t have reason to think they’d be repeated by the individual.