Critics of a lethal injection drug that has been used in problematic executions in several states say Thursday's execution in Alabama provides more evidence that it shouldn't be used to put inmates to death.
Smith's attorney's petitioned the U.S. Supreme Court to stay his execution on the grounds that the judicial override was unjust.
After the execution, a reporter asked Alabama Department of Corrections Commissioner Jeff Dunn about Smith's apparent struggle for breath during the process.
When the warden asked Smith whether he wanted to comment before his execution began, Smith responded, "No ma'am". Dunn said a required autopsy will determine if there any irregularities.
Smith was convicted for the November 8, 1994, shooting death of Huntsville store clerk Casey Wilson.
Smith's lawyers also tried other arguments, including that a jury had sentenced him not to death, but life in prison without parole.
However, trial judge Lynwood Smith, now a federal judge, imposed a death sentence, as allowed by state law. "But no autopsy can measure the extent of Ron Smith's suffering as he died", according to the public defender's statement.
The Supreme Court re-instated the death penalty in 1976 after having suspended it earlier in the 1970s.
After the midazolam was administered, a consciousness check was conducted per Department of Corrections protocol.
The US Supreme Court twice halted Smith's execution as his lawyers argued for a delay. Inmates have continued to challenge its use, saying it is a sedative, not an anesthetic, and can not reliably render a person unconscious.
At the beginning of his execution, Smith heaved and coughed repeatedly, clenching his fists and raising his head.
Ronald Bert Smith Jr was still alive after two consciousness tests and was seen coughing and heaving before he finally died.
In a consciousness test, a prison officer says the inmate's name, brushes his eyelashes and then pinches his left arm.
OH and Arizona have used midazolam as the first in a two-drug protocol. During the first one, Smith moved his arm. A second check was performed 10 minutes later.
The justices were again split 4-4 on whether to issue a stay, but Chief Justice John Roberts then cast a courtesy vote, allowing Arthur's execution to be delayed.
Smith's execution is the state's second this year after a brief hiatus caused by a shortage of execution drugs as well as legal challenges to the drugs administered.
Either way, the execution is likely to become an issue in lawsuits by death row inmates who claim the first drug in Alabama's lethal injection procedure doesn't ease the pain for the two fatal drugs that follow.
"I think we saw last night what we, unfortunately, have seen so many times before, which is that midazolam, which was never meant to be used this way, is not effective and can't be used this way", said Cassandra Stubbs, who directs the capital punishment project of the American Civil Liberties Union.
OH and Arizona have used midazolam as the first in a two-drug protocol. MS and Arkansas, which have not executed an inmate in several years, have also announced plans to use the sedative. His parents and son had visited him before he was put to death. In Ohio, Dennis McGuire gasped and convulsed for 10 minutes before dying.
Alabama changed its drug protocol a few years ago after drug manufacturers began declining to sell their drugs to it and other states for executions. Christopher Brooks was executed in January for a 1992 rape and murder.
Escambia County Medical Examiner Dr. Dan Raulerson said Friday that the coroner's office transported the executed inmate's body for examination by one of the doctors at the state forensics laboratory in Mobile.