Mistakes occurred. Inmates appeared to suffer in the gas chamber. Electric chairs caught fire or malfunctioned and didn't kill. So a growing number of law enforcement officials, legislators and advocates began searching for a foolproof, constitutional method for executions.
In 1977, an Oklahoma medical director appeared to have found a solution. Dr. Jay Chapman came up with a three-drug combination that promised to put the inmate to sleep before painlessly and quickly drifting off to death. Chapman's formula replaced the state's use of the electric chair.
Now, calls are mounting to scrap lethal injection, even by those who support capital punishment like Chief Judge Alex Kozinski of the 9th U.S. Circuit Court of Appeals. He believes a completely humane method of execution isn't possible and favors firing squads.
"If we as a society cannot stomach the splatter from an execution carried out by a firing squad, then we shouldn't be carrying out executions at all," Kozinski wrote Monday in support of carrying out Wood's execution.
Chapman's three-drug combination became the default execution method for the federal government and in every state — some three dozen — that has capital punishment. Lethal injection was embraced as the best possible way to execute and the apparent painless and swift death it caused were seen as attributes to counter lawsuits and protests that claimed capital punishment was cruel and unusual.
Since then, more than 1,200 inmates have been executed by lethal injection. The U.S. Supreme Court in 2008 ruled the method constitutional.
"Execution by lethal injection should be a humane way to die," said Arthur Caplan, head of medical ethics at New York University's Langone Medical Center. "But it isn't."
Caplan said that there hasn't been any reported trouble with physicians who in some states can legally help people commit suicide. "So we know it can be done painlessly," he said.
But medical ethicists and professional licensing boards for doctors and nurses forbid their participation in executions, which are carried out by lay workers who sometimes struggle with administering a lethal injection.
Further, pharmaceutical companies are refusing to ship prisons the three drugs necessary to mimic Chapman's mixture. That has caused prison officials to scramble to find alternative drugs that may not kill as quickly. Anesthesiology experts say they're not surprised that the two drugs Arizona used Wednesday took so long to kill Joseph Rudolph Wood.
So the lawsuits and protests persist. So do the problems.
On Wednesday, Wood gasped for air for 90 minutes and took about two hours to die after receiving an injection. An Ohio inmate gasped in similar fashion for nearly 30 minutes in January. An Oklahoma inmate died of a heart attack in April, minutes after prison officials halted his execution because the drugs weren't being administered properly.
Previously, non-medical personnel had trouble delivering the lethal injection or had trouble finding veins on longtime drug abusers. When doctors were called in to assist, the American Medical Association objected that it was unethical for physicians to be directly involved in executions.
Erwin Chemerinsky, dean of the University of California, Irvine law school and death penalty opponent, said the public would never stand for firing squads.
"It is far too gruesome," he said.