BONNE TERRE, Mo. - A Missouri man who killed a jeweler during a 1991 robbery was executed for the crime late, marking the state's third lethal injection in as many months.

Herbert Smulls, 56, was executed by a lethal injection late Wednesday of pentobarbital at the state prison in Bonne Terre. He was convicted of killing Stephen Honickman and badly injuring his wife, Florence, during a robbery at their jewelry shop in suburban St. Louis on July 27, 1991.

Smulls did not have any final words. The process was brief, Smulls mouthed a few words to the two witnesses there for him, who were not identified, then breathed heavily twice and shut his eyes for good. He showed no outward signs of distress.

He was pronounced dead at 10:20 p.m., nine minutes after the process began.

Florence Honickman spoke to the media after the execution, flanked by 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."

Smulls' attorney, Cheryl Pilate, had filed numerous appeals challenging the state's refusal to disclose where it obtained its execution drug, pentobarbital, saying that refusal made it impossible to know whether the drug could cause pain and suffering during the execution.

The U.S. Supreme Court had granted a stay late Tuesday, shortly before the scheduled 12:01 a.m. Wednesday execution, but the high court cleared numerous appeals on Wednesday night — even the one Pilate filed less than 30 minutes before Smulls was pronounced dead, though the final 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, "I'm not familiar that."

The state had maintained that the company was part of the execution team, so its name was protected from public disclosure.

Attorney General Chris Koster said in a statement after the execution: "My thoughts and prayers are with Florence Honickman and the family and friends of Stephen Honickman."

Prosecutors said the defence's arguments were simply a smoke screen aimed at sparing a murderer's life.

"It was a horrific crime," St. Louis County prosecutor Bob McCulloch said on Tuesday. "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."

Smulls had already served time in prison for robbery when he went to F&M Crown Jewels in Chesterfield and told the Honickmans, who owned the store, that he wanted to buy a diamond for his fiancee. But Smulls planned to rob the couple, and took 15-year-old Norman Brown with him.

"They planned it out, including killing people, whoever was there," McCulloch said.

Smulls began shooting inside the shop, and he and Brown took rings and watches — including those that Florence Honickman was wearing. She was shot in the side and the arm, and feigned death while lying in a pool of her own blood.

"I felt pain and terror while I lay on the floor playing dead while the murderers ransacked our office," Florence Honickman said Wednesday night.

She was the one to identify the assailants. Brown was convicted in 1993 of first-degree murder and other charges, and sentenced to life without parole. Smulls got the death penalty.

Smulls' execution was the state's third since it began using pentobarbital as its lethal injection drug.

Missouri and other states had used a three-drug execution method for decades, but pharmaceutical companies stopped selling the drugs in recent years for use in executions. Missouri eventually switched to pentobarbital, which was used to execute serial killer Joseph Paul Franklin in November and Allen Nicklasson in December. Neither inmate showed outward signs of distress.

Honickman's daughter, Mindy Wilner, was critical of the media questioning whether the drug could cause suffering for Smulls, saying it was the victims who suffered.

The state said it obtained its supply of the drug from a compounding pharmacy, which custom-mix drugs for individual clients. They are not subject to oversight by the U.S. Food and Drug Administration, though they are regulated by states.

Pilate said she and her defence team used information obtained through open records requests and publicly available documents to determine that state obtained its drugs from The Apothecary Shoppe, a compounding pharmacy based in Tulsa, Oklahoma. In a statement, the company would neither confirm nor deny that it made the Missouri drug.

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.

Pilate said the possibility that something could go wrong persists, citing recent trouble with execution drugs in Ohio and Oklahoma. She also said that previous testimony from a prison official indicates Missouri stores the drug at room temperatures, which experts believe could taint the drug, Pilate said, and potentially cause it to lose effectiveness.

Missouri Senate Democratic Leader Jolie Justus introduced legislation this week that would create an 11-member commission responsible for setting the state's execution procedure. She said ongoing lawsuits and secrecy about the state's current lethal injection method should drive a change in protocol.

News from © The Associated Press, 2014