A death-row inmate in Alabama cannot remember the crime he committed decades ago (due to dementia) and now there is an argument that it be unethical to execute someone who cannot remember why they are being executed:
I find a couple of things troubling about this argument:
First of all, that if it is unfair to execute someone who cannot remember their crime, then further incarceration of him would also be unfair by the same logic. Yes, incarceration is a milder form of punishment than execution, but it is still the same principle - he would be being denied his liberty because of a crime he cannot remember. Should he be set free?
I also think it opens a legal can of worms if we say that whether someone should suffer consequences for an action is tied to whether they can remember their action or not. There are drunk drivers who hit people with their cars and then later on cannot remember doing so due to their inebriation.