The Supreme Court. (Pablo Martinez Monsivais/AP)

The Supreme Court’s decision on Monday to uphold a controversial lethal injection procedure used by Oklahoma was reached because the five justices in the majority were not swayed by arguments that a particular sedative caused executions that could be deemed cruel and unusual punishment.

But in one of the dissents, Justice Stephen G. Breyer said he disagreed with the decision before moving on to a much larger question: Is the death penalty itself unconstitutional?

“I believe it highly likely that the death penalty violates the Eighth Amendment,” Breyer wrote. “At the very least, the Court should call for full briefing on the basic question.”

In a 41-page dissent — longer than the majority opinion authored by Justice Samuel A. Alito Jr., and 46 pages if you include appendices — Breyer, who was joined by Justice Ruth Bader Ginsburg, wrote that country’s use of the death penalty has dramatically changed since the court upheld capital punishment in 1976.

In a 5-4 ruling, the Supreme Court voted to uphold the use of a sedative called midazolam as part of states' lethal injection procedure. (Reuters)

He went on to say that these changes, combined with his two decades on the high court, have convinced him that the death penalty likely violates the Eighth Amendment prohibition against cruel and unusual punishment.

[Oklahoma says it will now use nitrogen gas as its backup method of execution]

“In 1976, the Court thought that the constitutional infirmities in the death penalty could be healed; the Court in effect delegated significant responsibility to the States to develop procedures that would protect against those constitutional problems,” Breyer wrote. “Almost 40 years of studies, surveys, and experience strongly indicate, however, that this effort has failed.”

In his dissent, Breyer pointed to several issues that he said create constitutional problems with the death penalty. These problems, which are familiar to anyone who follows the death penalty in the United States in recent years, combine to show “a serious problem of reliability,” Breyer wrote.

Meanwhile, in response to Breyer’s dissent, Justices Antonin Scalia and Clarence Thomas each filed an opinion dismissing these arguments, both criticizing him for suggesting that the judiciary — rather than the people — should abolish the death penalty. Scalia, who is known for his fiery opinions, wrote that Breyer “does not just reject the death penalty, he rejects the Enlightenment.”

Breyer, in his dissent, highlighted cases of innocent people who have been sentenced to death over the years, including men in Louisiana and North Carolina who spent three decades on death row before being released. (Most Americans — including big majorities of those who favor and oppose the death penalty — agree that innocent people can be put to death under the current system.) In addition, Breyer pointed to the FBI’s admission that its forensic examiners gave flawed testimony that resulted in more than 30 death sentences.

[‘It was fundamentally unfair.’ A prosecutor apologizes for his role in putting an innocent man on death row]

But Breyer also raised another concern that has been discussed before, most notably in a federal judge’s order last year — that of a system functioning arbitrarily. He cited studies that have found differences in how death sentences are handed down depending on the race of the victims and the accused, and he noted that he has found, after looking at thousands of death penalty cases, “discrepancies for which I can find no rational explanation.”

“The imposition and implementation of the death penalty seems capricious, random, indeed, arbitrary,” he wrote. “From a defendant’s perspective, to receive that sentence, and certainly to find it implemented, is the equivalent of being struck by lightning.”

He also pointed to another reality for people sentenced to death — what he termed the “unconscionably long delays that undermine the death penalty’s penological purpose.” People sent to death row are unlikely to be executed in a timely manner, if at all, owing to a combination of appeals, problems with carrying out executions and exonerations.

Death-row inmates across the country have spent an average of 14 years there, while the number of executions has been steadily dropping. The death-row population has been shrinking, but not because of executions; rather, inmates are leaving death row because courts are overturning their sentences or convictions, or they are dying of other causes. Indeed, Breyer said that these long stints are themselves troubling, because the inmates are generally in isolation, and solitary confinement has been found to cause catastrophic psychological effects.

As an example of the practice’s declining usage, Breyer noted the recent news that Nebraska just became the 19th state to formally abolish the death penalty (in addition to other states where executions are on hold or have not taken place for years). He also said that the “unusual” part of cruel and unusual is borne by the increasing rarity of executions: The number of inmates put to death each year continues to shrink, dropping last year to the lowest number in two decades, and these executions are taking place in an increasingly small pool of places. Last year, four out of five executions occurred in just three states (Texas, Missouri and Florida). Rare executions, and capital sentences that are never implemented at all, Breyer wrote, undermine the concept of a death sentence as a means of deterrence or retribution.

Still, Breyer acknowledged the dilemma posed by a fair system — one that has courts reviewing death sentences at every level — because that system will also carry with it inevitable delays. This is what he said ultimately backs up the idea that the death penalty violates the Constitution.

“In this world, or at least in this Nation, we can have a death penalty that at least arguably serves legitimate penological purposes or we can have a procedural system that at least arguably seeks reliability and fairness in the death penalty’s application,” he wrote. “We cannot have both.”

Breyer said he understands the argument allowing for states to make their decisions. But, he wrote, the last four decades have shown that responses from the states have not worked.