Lethal injection is dying a slow death. Thanks to a European Union embargo on the export of key drugs, and the refusal of major pharmaceutical companies to sell them, the nation’s predominant method of execution is increasingly hard to perform. Texas, the most prolific of death-penalty states, has only one dose of its preferred drug pentobarbital remaining. Other state death rows have seen their stocks dwindle too. Even if the justices uphold Oklahoma’s controversial lethal-injection protocol when they rule on the case later this term, the drug shortages show no sign of abating.

With lethal injection’s future uncertain, some states are turning to previously discarded methods. The Utah legislature approved a bill on Tuesday that would reintroduce firing squads for executions. On Wednesday, Alabama’s House of Representatives voted to authorize the electric chair if new drugs couldn’t be found. Electrocution is also being considered in Virginia and Tennessee. In Oklahoma, where the use of midazolam is currently before the U.S. Supreme Court, state legislators are mulling the gas chamber.

There’s a grim irony to this trend: Lethal injection became so widely adopted in the first place because the methods preceding it were considered untenable. Virtually all executions in the United States since 1776 used one of five methods: hanging, firing squad, electrocution, the gas chamber, or lethal injection. This graph by Quartz shows the change in methods over time. (The Supreme Court effectively halted executions between 1972 and 1976.)


Quartz

The driving force behind the creation and abandonment of execution methods is the constant search for a humane means of taking a human life. Arizona, for example, abandoned hangings after a noose accidentally decapitated a condemned woman in 1930. The state turned to the gas chamber three years later and used it for executions until 1992, when witnesses to Donald Harding’s execution described “a gruesome scene: Mr. Harding gasping, shuddering, and desperately making obscene gestures with both strapped-down hands” as he died. Arizona legislators adopted lethal injection shortly thereafter. This too proved fallible: In a botched execution last year, Joseph Wood spent almost two hours gasping in apparent distress before dying.

For the first half of American history, hanging was the predominant method of execution. Although relatively easy to set up, an improperly performed hanging could lead to death by strangulation or, as in Arizona, decapitation. The hangman’s noose was an iconic feature of frontier justice in the old American West, but its association with lynchings of African Americans after Reconstruction also transformed it into a symbol of extrajudicial terror. No state is currently considering its revival.

Electrocution marked the first attempt to make American capital punishment more palatable. New York successfully implemented the electric chair with the execution of William Kemmler in 1890. Eleven other states adopted the method by 1915, “motivated by the well-grounded belief that electrocution is less painful and more humane than hanging.” But the method was also prone to problems. In 1947, Willie Francis, a 16-year-old black juvenile found guilty of murder in Louisiana by an all-white jury, survived electrocution when the chair malfunctioned. He petitioned the Supreme Court and argued that a second attempt would violate his Fifth Amendment protections against double jeopardy and the Eighth Amendment’s prohibition of cruel and unusual punishment. The justices ruled 5 to 4 that it did not, and he was successfully executed in the same chair shortly thereafter.

More botched electrocutions followed over the next few decades, but the Supreme Court, which has never struck down a method of execution as unconstitutional, refused to intervene. In a particularly graphic dissent in 1985, Justice William Brennan described the physical damage that the electric chair produces at length:

Witnesses routinely report that, when the switch is thrown, the condemned prisoner "cringes," "leaps," and "fights the straps with amazing strength." The hands turn red, then white, and the cords of the neck stand out like steel bands. The prisoner's limbs, fingers, toes, and face are severely contorted. The force of the electrical current is so powerful that the prisoner's eyeballs sometimes pop out and "rest on [his] cheeks."

After the Supreme Court lifted a de facto moratorium on the death penalty in 1977, lethal injection began to replace electrocution in most states, but it endured in others. Florida’s electric chair, affectionately nicknamed “Old Sparky” by prison staff, became infamous for its malfunctions. After flames erupted from Pedro Medina’s head during his 1997 execution, Florida Attorney General Bob Butterworth told reporters, “People who wish to commit murder, they better not do it in the state of Florida because we may have a problem with our electric chair.”

Some states dabbled in other methods when replacing hanging. Utah kept the firing squad as an option, but few inmates chose it. The last death by firing squad took place in 2010 when inmate Ronnie Lee Gardner requested it instead of lethal injection. After Gardner’s execution, guards who participated received commemorative coins. Nevada pioneered the use of gas in the 1920s, whereby the condemned would be locked within a stone or steel vault that would fill with clouds of hydrogen cyanide. A handful of other states also adopted it before switching to lethal injection.

Lethal injection enjoyed tremendous popularity for two reasons. First, it produced an unparalleled record of seemingly painless deaths under the standard three-drug cocktail of sodium thiopental, vercuronium bromide, and potassium chloride. New drug cocktails have since negated this advantage. Second, and perhaps more importantly, lethal injection strongly resembled a medical procedure, thereby projecting our preconceived notions about modern medicine—its competence, its efficacy, and its reliability—onto the capital-punishment system. But such associations cut both ways. As states revert to earlier methods of execution—techniques once abandoned as backward and flawed—they run the risk that the death penalty itself will be seen in the same terms.