Lawyers for 33 death row inmates will argue Thursday before the Tennessee Supreme Court that the state's execution methods are "cruel and unusual."
It's a case that could help determine whether lethal injection remains legal in the United States.
The suit, Stephen West, et al. v. Derrick Schofield, et al., is one of several across the country that challenge lethal injection. It differs from many others in that it centers on the use of a particular sedative called pentobarbital.
Twenty states have either used the drug or have plans to. But it's never been determined to be constitutional, says the Death Penalty Information Center's Robert Dunham.
He says it's likely the federal courts will be asked to take up the question regardless of how the Tennessee Supreme Court rules.
"If it turns out in favor of the state, it's very likely that the death row prisoners will file what's called a petition for certiorari asking the United States Supreme Court to review the decision," says Dunham. "And if the prisoners win, and they win on federal law grounds, it's likely that the state prosecutors will ask the United States Supreme Court to review the decision."
The case also raises interesting legal questions about whether states can break their own laws or federal statutes in order to perform an execution, Dunham says.
The plaintiffs in the West case argue Tennessee's contract with its supplier prohibits it from using pentobarbital in a way that hasn't been approved by federal regulators. Lawyers for the state of Tennessee say that's a matter between the government and the supplier — not one that concerns prisoners on death row.
Lethal injection remains the main method of execution nationwide, though it faces an uncertain future. Pharmaceutical companies have stopped supplying the drugs needed, leading Tennessee and many other states to turn to compounding pharmacies. States have fought to keep the identities of these suppliers confidential, to prevent them from being pressured into not selling the drugs.
Courts have also questioned whether the current methods are as painless as states have claimed. Other states have used a sedative called midazolam, instead of pentobarbital, but in executions involving that drug, witnesses have reported seeing prisoners snoring, gasping for breath or waking in the middle of the procedure.
Those are among the reasons why Tennessee hasn't put anyone to death for nearly seven years.
Gov. Bill Haslam has not shown any inclination to speed executions, but if the courts do strike down lethal injection, Tennessee lawmakers have approved a fallback — the electric chair.
But that method also faces constitutional questions that would likely have to be resolved before the state of Tennessee could use it in executions.