Officials said that death row inmate Alan Miller's execution was halted by the state of Alabama Thursday evening due to an inability to meet protocols before a midnight deadline.

His execution was abandoned at around 11.30 p.m. on Thursday. It was half an hour before the state's death warrant was set to expire, reported Sky News. His execution by lethal injection was scheduled after a U.S. Supreme Court ruling earlier Thursday vacated a lower court injunction in a long-running dispute. It was over whether Miller would die by lethal injection or nitrogen hypoxia. It is an untested and unproven method that Alabama officials had said they were not ready to use, reported CNN.

State officials said that after the Supreme Court ruled the execution could proceed by lethal injection, but they couldn’t access the inmate’s veins within time limits.

Alabama Department of Corrections Commissioner John Hamm, said that due to the time constraints resulting in the slowness of the court proceedings, the "execution was called off." It was done once it was determined the "condemned’s veins could not be accessed in accordance with our protocol before the expiration of the death warrant." Hamm shared that Miller was returned to his cell on death row.

Governor Kay Ivey's office said in a statement that she “anticipates that the execution will be reset at the earliest opportunity." She shared that despite the circumstances that led to the cancellation of Miller’s execution, "nothing will change the fact that a jury heard the evidence of this case and made a decision." Ivey added that it does not change the fact that Miller "never disputed his crimes, and it does not change the fact that three families still grieve."

He was sentenced to death for the killings of his co-workers Lee Michael Holdbrooks, Terry Lee Jarvis and Christopher S. Yancy. They were all fatally shot in 1999.

A forensic psychiatrist who testified for his defense had determined that he was mentally ill and suffering a delusional disorder. It led him to believe that the victims were spreading rumors about him. But the psychiatrist concluded that the inmate’s mental illness didn’t meet the standards for an insanity defense in Alabama.

Meanwhile, a federal judge on Friday ordered Alabama to preserve records and medical supplies that were associated with the lethal injection attempt, reported ABC News. U.S. District Judge R. Austin Huffaker Jr. issued the order at the request of the inmate’s lawyers. They are trying to gather more information about what happened during Alabama’s attempt to execute the 57-year-old inmate.

Representation image. Pixabay.