I mean, there are cases where you have clear video evidence of murder, or mass shootings where it's obvious who the killer was with 100 witnesses.
If a proposal came to redefine the threshold for the death penalty from "beyond reasonable doubt" to "irrefutable" then the arguments here would not hold.
Video isn't truly irrefutable. Two people can look at the same video and draw different conclusions. You can see this anywhere from instant replay review in sports to some people's reactions to the Chauvin verdict.
also, given the collective (non-)evidence, we should expect that the number of people who are irredeemably and imminently threatening, and therefore truly deserving of the death penalty, to be extraordinarily small, like 5 sigma, rather than 2-3 sigma, which seems to be the mental model implicit in our justice system.
with such extraordinarily tiny incidence rates and an erroneous implicit mental model, it's no surprise that we misidentify the truly irredeemable so often. our implicit expectations simply get in the way of being impartial and objective.
If a proposal came to redefine the threshold for the death penalty from "beyond reasonable doubt" to "irrefutable" then the arguments here would not hold.