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.
That statute, as amended following Furman v. Georgia, 408 U.S. 238 (where this Court held to be violative of those Amendments death sentences imposed under statutes that left juries with untrammeled discretion to impose or withhold the death penalty), retains the death penalty for murder and five other crimes.