An appeal was pending before the United States Supreme Court asking to halt Herbert Smull's execution was ultimately denied... 30 minutes after his death.

In 1991, Herbert Smulls called a jeweler to make an appointment to shop at the man's suburban St. Louis store. He said he wanted to buy a diamond for his fiancee.

But it was a set up. Smulls planned to rob the store. More than two decades after the heist, he was executed Wednesday for fatally shooting the store owner.

Stephen Honickman's wife, Florence, was also shot, but survived by playing dead in a pool of her own blood until Smulls and a 15-year-old accomplice left.

It was Missouri's third execution since November and the third since switching to a new drug, pentobarbital, for the lethal injection.

Smulls, 56, did not make a final statement. He mouthed a few words to his two witnesses, who were not identified, then breathed heavily twice and shut his eyes for good. He was pronounced dead at 10:20 p.m.

Honickman spoke to the media after the execution, alongside her adult son and daughter. She questioned why it took 22 years of appeals before Smulls was put to death.

"Make no mistake, the long, winding and painful road leading up to this day has been a travesty of justice," she said.

Smulls' attorneys spent the days leading up to the execution filing appeals that questioned the secretive nature of how Missouri obtains the lethal drug, saying that if the drug were inadequate, the inmate could suffer during the execution.

The U.S. Supreme Court granted a temporary stay late Tuesday before clearing numerous appeals Wednesday, including the final one that was filed less than 30 minutes before Smulls was pronounced dead. The denial came about 30 minutes after his death.

When asked about the time between the appeal and the execution, Missouri Department of Corrections spokesman Mike O'Connell said he was "not familiar with that."

Like Joseph Paul Franklin in November and Allen Nicklasson in December, Smulls showed no outward signs of distress in an execution process that took about nine minutes.

Since 1989, Missouri had used a three-drug protocol for executions, but drug makers have stopped selling those medications for executions. Missouri switched late last year to a form of pentobarbital made by a compounding pharmacy that it refuses to name.

Since the compounding pharmacy is part of the execution team, state officials say, they are not required to disclose its name.

Smulls had a troubled life from the start. Born to an unwed 15-year-old in St. Louis, he was passed along to two other caregivers while still a toddler. As a young man, he turned to crime and spent time in prison for robbery.

In the summer of 1991, he decided to rob again.

Honickman's F&M Crown Jewels in the tony St. Louis suburb of Chesterfield was open by appointment only. The robbery quickly turned violent. Honickman, shot and dying on the floor, pleaded with Smulls to stop.

"Enough already. Take what you want," Honickman said, according to his wife's testimony. The robbers took rings and watches, including the ones Florence Honickman was wearing.

The attackers apparently thought she was dead. After being shot in the side and the arm, she was lying motionless in her own blood.

When police stopped Smulls 15 minutes later, they found stolen jewelry and weapons in his car, St. Louis County prosecutor Bob McCulloch said. Florence Honickman identified the assailants.

Smulls' accomplice, Norman Brown, was sentenced to life in prison without parole.

"It was a horrific crime," McCulloch said. "With all the other arguments that the opponents of the death penalty are making, it's simply to try to divert the attention from what this guy did, and why he deserves to be executed."

Compounding pharmacies custom-mix drugs for individual clients and are not subject to oversight by the U.S. Food and Drug Administration, though they are regulated by states.

Smulls' attorney, Cheryl Pilate, said the secrecy surrounding where the pentobarbital is made makes it impossible to know whether the drug could cause pain and suffering during an execution. She cited recent trouble with execution drugs in Ohio and Oklahoma.

Using information obtained through open records requests and publicly available documents, Pilate said, her defense team determined that the compounding pharmacy is The Apothecary Shoppe, based in Tulsa, Okla. In a statement, the business would neither confirm nor deny that it makes the Missouri drug.

Previous testimony from a prison official indicates Missouri stores the drug at room temperature, Pilate said, a practice that experts believe could taint it and cause it to lose effectiveness.