An Alabama inmate seeking to block the state’s attempt to make him the second person put to death by nitrogen gas has filed a lawsuit arguing the first execution under the new method was “botched” and caused cruel and prolonged suffering.

Attorneys for Alan Eugene Miller, who survived a 2022 lethal injection attempt, filed the lawsuit Friday in federal court in which they challenged the execution method and asked a judge to prevent a potential execution from going forward.

Miller’s attorneys argued that the first nitrogen execution in January left Kenneth Smith shaking and convulsing on a gurney as he was put to death. The suit argued that it would be a violation of the ban on cruel and unusual punishment to put him to death using the same protocol, which used a mask to deliver the nitrogen gas. They also argued the state is seeking to execute Miller to “silence” him in retaliation for speaking out about his failed lethal injection attempt, calling that a violation of his free speech and due process rights.

“Rather than address these failures, the State of Alabama has attempted to maintain secrecy and avoid public scrutiny, in part by misrepresenting what happened in this botched execution,” the lawyers wrote. They said Alabama was unable to conduct such an execution “without cruelly superadding pain and disgrace, and prolonging death.”

A spokeswoman for Alabama Attorney General Steve Marshall did not immediately respond to a text message seeking comment on the lawsuit.

In February, Marshall’s office asked the Alabama Supreme Court to set an execution date for Miller using nitrogen gas. The court has not yet ruled on the request. Miller is scheduled to file a response with the court this week.

People protest the planned execution by nitrogen hypoxia of Kenneth Eugene Smith at the state capitol building in Montgomery, Alabama, on January 23, 2024. Smith was the first U.S. inmate executed using nitrogen gas, and Alan Eugene Miller is suing in a bid to block the state’s attempt to make him the second. (Mickey Welsh / USA TODAY NETWORK)

The request for an execution date comes as the state and advocates continue to present opposing views of what happened during the state’s first execution using nitrogen. Smith shook and convulsed in seizure-like movements for several minutes on the death chamber gurney as he was put to death on Jan. 25.

Miller was sentenced to death after being convicted of a 1999 workplace rampage in which he killed Terry Jarvis, Lee Holdbrooks and Scott Yancy.

Like Smith, Miller survived a previous lethal injection attempt. The state attempted to execute Miller by lethal injection in September 2022, but that execution was called off after officials were unable to insert an intravenous line into the 351-pound prisoner’s veins.

After that attempt, the state struck an agreement with Miller’s lawyers that it would never again seek to execute Miller by lethal injection and that any attempt to execute him in the future would be done with nitrogen gas. However, Miller’s attorneys argued that witness accounts of Smith’s execution contradict Marshall’s assertion that it was “textbook” and went according to the state’s plan.

A separate lawsuit filed by another death row inmate seeking to block the use of nitrogen gas said witness accounts show that Smith’s execution was a botched “human experiment.”

An attorney listed for Miller did not immediately respond to an email seeking comment on the lawsuit.

Miller said that during the aborted 2022 lethal injection attempt, prison staff poked him with needles for over an hour as they tried to find a vein and at one point left him hanging vertically as he lay strapped to a gurney.

Miller, a delivery truck driver, was convicted in the fatal workplace shootings of the three men. Prosecutors said Miller killed Holdbrooks and Yancy at one business and then drove to another location where he shot Jarvis. Each man was shot multiple times.

Testimony at Miller’s trial indicated Miller was delusional and believed the men were spreading rumors about him. Jurors convicted Miller after 20 minutes of deliberation and then recommended a death sentence, which a judge imposed.