There are lots of ways to execute a prisoner. But in the U.S., at least, the 32 states that still execute prisoners have decided on lethal injection. On its face, lethal injection seems like a clinical, modern, hopefully low-pain, and usually low-key way to kill somebody. Except when it isn't, as we saw in last year's crop of botched executions.

The prolonged, evidently painful deaths of Clayton Lockett in Oklahoma, Joseph Wood in Arizona, and Dennis McGuire in Ohio were tied to experimental drug cocktails necessitated by a shortage of traditional death drugs. This shortage is due largely to a ban by European countries on exporting certain drugs to U.S. states that practice capital punishment.

The free market is making a case against capital punishment. So far, the states that actively execute prisoners have been willfully plugging their ears.

But now, Texas is down to its last dose of pentobarbital, the lethal injection drug it has used since 2012. As other states' supplies of proven drugs dry up, they're working toward dusting off old methods — firing squad (Wyoming, Utah), the electric chair (Tennessee), and even the gas chamber (Oklahoma).

From 1982, when Texas became the first state to use lethal injection, until 2011, the national three-drug cocktail was essentially the same: a sedative to numb the prisoner (sodium thiopental), a paralytic agent (pancuronium bromide) to immobilize him, and a drug (potassium chloride) to stop the heart.

Then, in 2011, Hospira, the only U.S. company that sold sodium thiopental, announced it would "exit the sodium thiopental market" entirely, after its Italian plant refused to send any of the sedative to the U.S. because of its use in capital punishment. When states' sodium thiopental stocks ran out, they turned to pentobarbital, used to induce comas and euthanize animals — until its Danish manufacturer, Lundbeck, found out and barred its sale to states that employ lethal injection. Other producers of the drug have also prohibited its sale to U.S. correctional facilities.

States then started using the sedative benzodiazepine midazolam — Lockett and Wood were midazolam guinea pigs — despite the wishes of its originator, Roche. States have also been ordering pentobarbital and other lethal-injection agents from domestic compounding pharmacies — but the details of those deals are extremely hazy.

With just a single dose of pentobarbital left and 317 inmates on death row, Texas is stocking up on midazolam. It's not clear if Texas can't get pentobarbital because the compounding pharmacies are refusing to sell it to them, or because they can't get the raw ingredients — the Professional Compounding Centers of America told The Texas Tribune that it stopped providing pentobarbital ingredients to its customers in January 2014.

Most compounding pharmacies aren't regulated by the Food and Drug Administration, and their products are uneven. Which compounding pharmacies are Texas, Oklahoma, Ohio, Georgia, Missouri, and other states buying drugs from? They're not saying.

Why not? "Disclosing the identity of the pharmacy would result in the harassment of the business and would raise serious safety concerns for the business and its employees," Texas Department of Criminal Justice spokesman Jason Clark explained to The Texas Tribune last month.

Georgia passed a law shielding its lethal injection drug sources from the public, and Missouri won a lawsuit from death row inmates who wanted to know what was in the lethal cocktail they were to be subjected to, who made it, and who quality-tested the drugs. In December, a Texas court ordered the state to reveal where it obtained its lethal injection drugs. (TDCJ is appealing, and doesn't have to name names during the appeals process.)

In April 2014, after Clayton Lockett's 45-minute death, The Washington Post's Brady Dennis and Lena H. Sun explained how states obtained their new drugs:

In their scramble to carry out death sentences, prison officials from different states have made secret handoffs of lethal-injection drugs. State workers have carried stacks of cash into unregulated compounding pharmacies to purchase chemicals for executions.... "It looks like a street-level drug deal," said Dean Sanderford, a lawyer for Lockett. "And they’re keeping all the information secret from us." [The Washington Post]

Just ponder that for a moment.

Providing lethal injection drugs to state prisons is so toxic that no European country will do it and no American company is willing to do it openly. Gunmakers and abortion clinics advertise their services, but pharmacies and drugmakers won't publicly associate with a form of punishment approved of by 63 percent of Americans.

That's the market talking, and it's saying it wants no part of this.

There are lots of reasons to oppose the death penalty. It is significantly more expensive than incarcerating prisoners for life. It doesn't appear to deter crime.* There's a good chance America has executed at least one innocent person. Capital punishment puts the state in control of life and death, and turns state employees into literal executioners.

The American Board of Anesthesiologists and the American Medical Association prohibit their members from helping administer capital punishment.

If you believe in free-market capitalism — and presumably a good number of the 76 percent of Republicans who favor capital punishment do — then the scarcity of lethal injection drugs should be a signal that life without parole may be a better option.

But, you may argue, what about the other forms of execution? Well, states are only returning to them reluctantly. And the reason seems to be that shooting people, hanging them, electrocuting them, and gassing them are too flamboyantly deathly for many Americans.

Lawmakers in Utah "stopped offering inmates the choice of firing squad in 2004, saying the method attracted intense media interest and took attention from victims," explain The Associated Press' Brady McCombs and Lindsay Whitehurst. And in 2010, when Utah's last prisoner "was put to death by five police officers with .30-caliber Winchester rifles," the execution "drew international attention."

If you take away the lab coats and the sedatives, capital punishment begins to look uncomfortably close to its probable purpose: State-sanctioned, ritualized revenge killings. (That's largely why my colleague Ryan Cooper wants to bring back the guillotine, the gallows, and the firing squad — to remind us of what we're really doing.)

Utah State Rep. Paul Ray (R) — the main proponent of bringing back the firing squad — says that when prison officials selected the five police officers to carry out past execution, they start in the areas where the crime happened. "We've always had a lot more volunteers than actually had spots," he tells AP.

Revenge is a very human emotion, and people assigned the death penalty typically committed really atrocious crimes. But justice is supposed to be rational and impartial.

When the U.S. 9th Circuit Court of Appeals declined to rehear a three-judge panel's decision to stay Wood's execution in July 2014, Chief Judge Alex Kozinski, a Reagan appointee, dissented, arguing that Arizona "should and will prevail in this case" and correctly predicting that the Supreme Court would lift the stay. But his dissent turned into a history lesson on lethal injection, which he called a flawed "enterprise doomed to failure":

Using drugs meant for individuals with medical needs to carry out executions is a misguided effort to mask the brutality of executions by making them look serene and peaceful.... But executions are, in fact, nothing like that. They are brutal, savage events, and nothing the state tries to do can mask that reality. Nor should it. If we as a society want to carry out executions, we should be willing to face the fact that the state is committing a horrendous brutality on our behalf.... If we, as a society, cannot stomach the splatter from an execution carried out by firing squad, then we shouldn’t be carrying out executions at all. [Kozinski]

If drug companies refuse to sell state prisons lethal drugs — perhaps they object to "subverting medicines meant to heal the human body to the opposite purpose," as Kozinski writes — the states may have no choice but to return to older methods, or risk subjecting their condemned wards to cruel and unusual punishment.

* "Much psychological and sociological research suggests that many criminal acts are crimes of passion or committed in a heated moment based only on immediate circumstances, and thus potential offenders may not consider or weigh longer-term possibilities of punishment and capture, including the possibility of capital punishment," says a February 12, 2015, report from NYU Law's Brennan Center for Justice. "In line with the past research, the Brennan Center's empirical analysis finds that there is no evidence that executions had an effect on crime in the 1990s or 2000s."