An Alabama inmate coughed and heaved for 13 minutes during his execution. Prior to his execution he repeatedly challenged the type of drugs which were set to be used, saying they didn’t provide enough sedation.

During the 13 minutes of the execution Smith appeared to be struggling for breath. He heaved and coughed and clenched his left fist, and raised his head, after apparently being administered the first drug, midazolam (a sedative), in the three-drug combination, according to AL.com.

US Supreme Court denies stay of execution of Ala Death Row inmate Ronald Bert Smith; execution can proceed at 8:15 https://t.co/eCOxPgDCyN — Kent Faulk (@krfaulk) December 9, 2016

A Department of Corrections captain performed two consciousness checks before administering the next two drugs to stop his breathing and heart. The tests involved calling out Smith’s name, brushing his eyebrows back and pinching him under his left arm.

“We do know we followed our protocol. We are absolutely convinced of that,” Alabama Corrections Commissioner Jeff Dunn told AP.

During 34 minute execution Smith heaved and coughed through about 13 minutes ... had 2 consciousness tests performed — Kent Faulk (@krfaulk) December 9, 2016

Death row inmate Ronald Bert Smith, 45 was executed Thursday night by lethal injection for the 1994 murder of Huntsville convenience store clerk Casey Wilson.

Wilson was pistol-whipped and then shot in the head by Smith during a robbery, court documents show.

A jury voted 7-5 to recommend a sentence of life imprisonment but a judge overrode the recommendation and sentenced Smith to death, likening the murder to an execution and accused Smith of ignoring Wilson’s pleas for mercy. Smith spent 21 years on death row.

Supreme Court rules Florida death penalty system unconstitutional https://t.co/BGMhSstB9Xpic.twitter.com/R5CaEBESFD — RT America (@RT_America) January 13, 2016

US Supreme Court justices had twice paused Smith’s execution after his lawyers argued the judge shouldn’t have imposed the death penalty after the jury recommended life imprisonment. Smith lawyers argued a recent Florida decision that ruled the state’s death penalty structure gave too much power to judges applied to his case. Four liberal justice said they would have halted the executive but needed five to do so.

Stay of execution granted to Alabama death row inmatehttps://t.co/hWj1DMG1WIpic.twitter.com/4oebp6JlhN — RT America (@RT_America) May 13, 2016

When asked about whether Smith’s movements during the execution should mean the process should be changed. Commissioner Dunn told AP to leave it to the experts.

“There will be an autopsy that will be done on Mr. Smith and if there were any irregularities those will hopefully be shown or born out in the autopsy. I think the question is probably better left to the medical experts,” said Dunn.

Alabama had a lull in executions caused by a shortage of execution drugs and litigation over the drugs used. The state executed Christopher Eugene Brooks in January over a 1993 rape and beating death of a woman. A judge had stayed two other executions scheduled this year.

Smith had separately challenged Alabama’s lethal injection protocol in court papers arguing the sedative was unreliable and could cause inmates to feel pain, citing its use in problematic executions. Side-effects of Midazolam are that it may cause severe breathing problems.

None of Smith’s family members attended the execution but two of his lawyers did witness it and had a problem with the way it was proceeding.

“He’s reacting,” one of Smith’s attorneys whispered to another, according to AP.

A member of the victim Casey Wilson’s family witnessed the execution.