He singled out one passage from Roberts' opinion in which the chief justice wrote that the new standard should go a long way toward resolving the legal challenges that have been filed around the country. "A State with a lethal injection protocol substantially similar to the protocol we uphold today would not create a risk that meets this standard," Roberts wrote.
That pronouncement is critical, Scheidegger said, noting that among the 35 states that execute by injection, the protocols "are all substantially similar. To the extent that they differ, it's because they go further to check on [the prisoner's] consciousness."
But Deborah W. Denno, a professor at the Fordham University School of Law who has written about the history of execution methods for nearly two decades, said the ruling "leaves a big door open for future litigation" and that some death row inmates could meet the new standard with evidence already presented in court.
"When you look at California, where six out of the last 11 lethal injections seem to be indicating that there wasn't sufficient [anesthetic], that's substantial. That's a substantial risk," she said. "With evidence like that, attorneys will be in pretty good stead."
Denno said states will have to stop their practice of keeping secret most things having to do with executions, such as prison manuals that lay out the steps to put an inmate to death and the autopsies that often include tests that gauge the amount of each of the three drugs in the prisoner's system.
In his concurring opinion, Justice Stevens seemed to express disappointment that the court's ruling would not conclusively "bring the debate about lethal injection as a method of execution to a close."
"Instead of ending the controversy, I am now convinced that this case will generate debate not only about the constitutionality of the three-drug protocol, and specifically about the justification for the use of the paralytic agent, ... but also about the justification for the death penalty itself," he wrote.
Recent decisions of state legislatures, Congress and the Supreme Court to retain capital punishment, Stevens wrote, "are the product of habit and inattention rather than an acceptable deliberative process."
In Maryland, the debate showed no signs of ebbing.
In a sharply worded letter to the governor, Republican leaders of the House of Delegates accused O'Malley of engaging in "a de facto suspension of the law" and called on him to immediately issue new execution procedures to begin the approval process.
