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.
Death Penalty for Offenses Other Than Murder - State and Federal Laws that allow Capital Punishment when no death has occurred. DPIC's Page on Kennedy v. Louisiana - Striking down the death penalty for non-homicide offenses against individuals. Those Executed Who Did Not Directly Kill the Victim. Aggravating Factors by State - Lists of the factors that could make a defendant eligible for the Death Penalty.