Content Warning: This editorial contains discussion of the death penalty and execution.

Two years after the April 15 Boston Marathon bombing, Dzhokhar Tsarnaev has reached the sentencing phase of his trial, but most of Massachusetts opposes the death penalty for him. Convicted on all 30 counts brought against him, of which 17 carry a possible death sentence, Tsarnaev faces either the death penalty or life imprisonment without the possibility of parole. If the case were up to the state of Massachusetts, Tsarnaev would not receive a death sentence. The death penalty is illegal in the state, and only about a third of its residents approve of the death penalty for egregious crimes. Less than 20 percent of the state population believes that Tsarnaev should be executed and only 15 percent of Bostonians are in favor of his execution.

Even several victims of the bombing — including the parents of the 8-year-old who was killed, a couple who both lost limbs in the bombing and the sister of the slain MIT police officer — have spoken out against the death penalty for the bomber.

Rather, the public prefers he receive a life sentence in a maximum security prison — a surprising and impressive fact given that Tsarnaev is responsible for an act of terror that killed four and injured 280 people. Unfortunately for Tsarnaev’s fate, the opinions of Massachusetts residents and even the state’s laws are irrelevant. The case is a federal matter, and jurors in a federal court will determine his sentence.

Even if Tsarnaev is sentenced to death, it’s likely that he might never be executed. Since the 1960s, the federal government has only executed three people, despite multiple death penalty sentences. A nationwide shortage of execution drugs combined with likely years of appeals in Tsarnaev’s defense might result in Tsarnaev dying a natural death in prison before his execution date.

The controversy surrounding Tsarnaev’s sentencing is emblematic of a larger debate on the death penalty and execution methods in the U.S. — especially surrounding the highly controversial method of lethal injection. On Wednesday, the Supreme Court heard a case brought by three inmates against the state of Oklahoma about the use of the sedative midazolam in lethal injection. According to the argument brought by the inmates, the sedative does not achieve the level of unconsciousness necessary for surgery and therefore violates the Eighth Amendment.

The Supreme Court’s nine justices seemed to split along ideological lines on the constitutionality of the drug on Wednesday, highlighting the deeper moral questions central to the death penalty debate. Wednesday’s courtroom debate, which was supposed to narrowly revolve only around the constitutionality of midazolam, erupted into a debate over the death penalty so heated that Chief Justice John Roberts had to reprimand the justices for their rudeness toward the attorneys. The death penalty brought out the worst in the Supreme Court justices, highlighting how visceral an issue it is, even for those who are supposed to be the country’s most objective decision makers.

Among the debates in the Supreme Court was the availability of alternative execution methods. Lethal injection is the most botched execution method, yet it is still the execution method of choice in the U.S. Between 1890 and 2010, 7.1 percent of lethal injections resulted in complications, compared to gas chambers at 5.4 percent. In contrast, among the 34 firing squad executions during that time, there were no complications. But lethal injection is easier for us to stomach. It feels removed and humane in a way that other methods do not. There is something about directly killing another human being that makes even the staunchest death penalty supporters uncomfortable.

The controversy over which execution method is the most humane is not the heart of the death penalty debate, and as nine impassioned justices demonstrated, it is a thin veil over deeper moral questions. While six in ten Americans still approve of the death penalty — a statistic that has remained constant since 2008 — the number of people who favor the death penalty over life in prison with no possibility of parole has decreased. This change might stem from a growing realization that the determination of guilt and innocence in the justice system is far from perfect. With the emergence of breakthrough scientific technologies such as DNA testing, many prisoners have been exonerated. It is nearly impossible to be completely certain that a suspect is guilty. Any amount of reasonable doubt is a valid reason to declare a stay of execution, especially since there are so many inmates executed who are exonerated later in light of DNA evidence. Life in prison with no possibility of parole is a bleak punishment, and some in that situation might even favor death, but even the faintest hope of appeal makes it at least more reversible than the death penalty.

The common thread throughout the growing disapproval of the death penalty is uncertainty — uncertainty in how we execute individuals and, more importantly, why we do it in the first place. The recent controversy on the Supreme Court and the small number of Bostonians who support Tsarnaev’s execution both suggest that Americans may finally be acknowledging the inherent inhumanity of the death penalty.