The Arizona corrections department has spent more than $2,000 on the ingredients required to make the deadly gas also known as hydrogen cyanide, and have conducted inspections to make sure that their gas chamber, which has been unused for 22 years, is in operable condition.
The Republican-controlled state has not carried out any executions since 2014 when a lethal injection went wrong, but they are now working towards reinstating capital punishment.
In 2014, the execution of Joseph Wood took two hours and 15 injections before he was declared dead. Since then, the state has not carried out any executions.
The last person to be executed in Arizona by gas was German national Walter LaGrand, who was convicted for armed robbery and executed in 1999. A witness account reported that it took him 18 minutes to die, and that he was coughing violently throughout.
After the execution of LeGrand, the gas chamber fell was not used again but now, officials are preparing it for use again.
One of the first inmates on death row set for execution is 65-year-old Frank Atwood, who was convicted of killing a child in 1984 but Atwood's legal team have objected, saying that the state is in a hurry to set an execution date despite an ongoing investigation their client's possible innocence.
They have also argued that the potassium cyanide purchased by the corrections department does not meet the state's execution protocol which explicitly demands that only sodium cyanide be used. This is not an insignificant detail, attorney Joseph Perkovich said.
“Frank Atwood is prepared to die. He is a man of Greek Orthodox faith and is preparing for this moment. But he does not want to be tortured and subjected to a botched execution," Perkovich added.
Despite Arizona's efforts to present their planned execution method as acceptable and reputable, the name Zyklon B is inextricably linked to the horrors of the past, when over a million Jews and others were murdered in Nazi gas chambers using the lethal gas between 1942 and 1945.