About 5-10% of deathrow inmates suffer from a severe mental illness (schizophrenia, bipolar, ptsd etc), it is illegal to execute the mentally disabled (mental retardation, yes that is the actual terms they use, I hate the R word but that's the legal term so don't bitch at me about it), but it is legal to execute criminals with this mental illnesses, in many cases of mentally ill death row inmates, they didn't know they had committed a crime or done anything wrong, especially the paranoid schizophrenics.