Ketamine was first developed in 1962. It is on the World Health Organization's List of Essential Medicines, the most important medication needed in a basic health system. It is legally sold under a very wide variety of brand names, including Ketalar.
If the crime you commit (generally just first degree murder) is in a state that does not have the death penalty then the only way you can be executed is if you are tried in a federal court as opposed to a state court.
Position Statement 54: Death Penalty and People with Mental Illnesses. Policy. Moratorium. People with serious mental illnesses are at a substantial disadvantage in defending themselves when they face criminal charges, and those difficulties are compounded when the charges are so serious that the death penalty is sought.