Executing Criminals Who Are Mentally Ill

I feel that states legally executing mentally ill people for crimes shouldn't be allowed because they can't control their actions or emotions as well as we can. They also lack the ability to choose from right to wrong, making them incapable to defend themselves in court. Mentally ill people who commit crimes should be entered in a facility where they can be treated and monitored, not be executed for something they don't understand was a crime. It surprised me that the court thinks Mr. Ferguson is lying about being mentally ill, even though he has been diagnosed for over 40 years. This article relates to the character Lennie, from Of Mice and Men, because both he and Mr. Ferguson are mentally ill and have committed a crime where people thought they should be killed.