The order makes Washington the 20th state to abandon the death penalty.
Nebraska experienced a series of firsts: its first execution in 21 years, its first lethal injection and the first ever fentanyl execution.
Companies that make and sell the drugs have restricted who can buy them, asked states to return them and even stopped making one to try to keep it away from lethal injections.
A drug company sued to stop Nebraska from using its product in an upcoming execution that would be the state's first lethal injection.
“I just want to say I’m really sorry,” Billy Ray Irick said before he was put to death with a cocktail that includes Midazolam.
Nevada and Nebraska have both announced unprecedented plans to use fentanyl in executions.
Attorneys for Danny Bible, 66, proposed other execution methods that they say would be more humane for the elderly and sick prisoner.
Authorities said the man was behind a string of explosives set off or sent to people in 1989.
Russell Bucklew killed and raped. His lawyers argue that execution by injection could cause his tumors to burst and drown him in blood.
It is the latest in a series of dramatic efforts some officials have made to continue carrying out death sentences.