In recent months there had been some question as to whether the sentence would be carried out as scheduled because Texas, like the rest of the United States, is suffering from a shortage of the drug it prefers to kill its citizens with, pentobarbital.

Pharmaceutical companies have declined to provide their drugs for use in executions.

As it turned out, Texas officials tracked down a fresh source, enough to execute Sprouse – who murdered two men at a petrol station in 2002 – as well as three other inmates whose execution has been set for this month.

It is not saying where it got the drugs from.

Also on Thursday the Boston Globe published an editorial calling on a jury to spare the life of Dzhokhar Tsarnaev, the 21-year-old who a day earlier had been found guilty on 30 charges relating to the bombing of the Boston Marathon.

The Tsarnaev case has spurred debate over the death penalty in America, and revealed just how divided the country is over the issue.

Tsarnaev's guilt had never really been at issue. The evidence against him was so overwhelming that rather than challenging it his legal team – the best in the business according to several people who spoke with Fairfax Media – had sought to save his life by portraying him as having been led into his crimes by a manipulative older brother, Tamerlan, who was killed evading arrest.

The federal attorney-general, Eric Holder – a man known to oppose capital punishment – directed prosecutors to pursue the death penalty. The sentencing phase of the trial has now begun.

Divided opinion

The Globe's editorial shocked many Americans, though perhaps it should not have. Ever since Tsarnaev help set the bombs that killed three and injured 263 Bostonians, a majority of the city's people have opposed his execution.

A poll commissioned for National Public Radio (NPR) and released on Monday showed 62 per cent of residents wanted to see him sentenced to life in prison, while 27 per cent called for the death penalty. Those numbers are consistent with polls that have been conducted since Tsarnaev was charged.

By contrast, a poll commissioned by NBC this week found 47 per cent of Americans believe he should be executed and 42 per cent would like to see him imprisoned for life, while 11 per cent were not sure.

And in Texas? A recent poll found 63 per cent of Texans support the death penalty and 33 per cent oppose it.

The Globe argued against Tsarnaev's execution on both philosophical and practical grounds.

"For death-penalty opponents, of course, it's a no-brainer: He should spend the rest of his life rotting in prison instead," wrote the newspaper's editorial board. "Sentencing Tsarnaev to death would ensure endless appeals, substitute vengeance for justice, and risk letting him become a martyr."

This is a criticism that has been levelled at federal prosecutors by many, especially those who believe that Tsarnaev should have been tried by the state of Massachusetts, which has banned the death penalty.

Had the death penalty been taken off the table it is likely Tsarnaev would have pleaded guilty, sparing victims and their families the trial and ongoing automatic appeals the death penalty sets in motion.

There are even those who speculated that the trial – and the federal government's pursuit of the death penalty – was part of a larger political picture.

The Obama administration is still being blocked by Republicans in Congress from moving Guantanamo Bay prisoners to the mainland so it can close the facility.

Some suggest the administration wants to prove it can try, convict and execute a terrorist through the civil justice system rather than the military.

Just as the debate of Tsarnaev's life and death goes on, the death penalty itself is being challenged across the country.

This debate too is being driven as much by practical concerns as philosophical.

Wrongly convicted

Many people – and indeed many state administrations – who instinctively support capital punishment are coming to the conclusion that the criminal justice system is incapable of fairly and properly administering it.

Since DNA technology became widely available, organisations like the Innocence Project have proved time and again that despite an appeals process that can drag on for many years, innocent people keep getting convicted of capital crimes. The Innocence Project itself has secured the exoneration of 316 wrongly convicted people, 18 of whom were sentenced to death. It has established the minorities are overrepresented among the ranks of the wrongly convicted.

Across America 1383 people have been found to have been wrongly convicted, according to the National Registry of Exonerations, while a study into 7482 death penalty cases between 1973 and 2004 published by the journal PNAS last year estimated more than  4 per cent of people sentenced to death were innocent. There have been two death row exonerations in the past month alone.

With the relentless revelations that innocent people are being sentenced to death many states are either banning or suspending the use of capital punishment.

Just last month the Governor of Pennsylvania, Tom Wolf, suspended the practice, saying in a statement, "This moratorium is in no way an expression of sympathy for the guilty on death row, all of whom have been convicted of committing heinous crimes. This decision is based on a flawed system that has been proven to be an endless cycle of court proceedings as well as ineffective, unjust, and expensive."

This follows moratoria in Washington, Colorado, Maryland, California, Kentucky, Arkansas and North Carolina.

Many other states have de facto moratoria in place and others, like Massachusetts ban the practice outright.

It is the growing controversy over the process that prompted the pharmaceutical companies to block the sale of their products for lethal injection. In turn this has led to some hideously botched executions as executors experimented with new drug cocktails.

Last year it took two hours for the state of Arizona to put Joseph Wood to death. Also last year in Oklahoma, Clayton Lockett was declared to be unconscious three minutes into his execution, before he woke, spoke, strained against his restraints, writhed, groaned and convulsed. It took him 43 minutes to die.

The Supreme Court will this month hear a case brought by another Oklahoma inmate whose lawyers are arguing that lethal injection constitutes a cruel and unusual punishment.

Alternative methods

While some states are turning away from the death penalty, the difficulty in obtaining the drugs – and in convincing qualified medical personal to use them – has prompted some states to consider alternatives.

Utah has just reintroduced the firing squad as an alternative and Arkansas might follow suit. Tennessee has reinstated its electric chair and Oklahoma is considering returning to the gas chamber – an option phased out after the horrors of World War II.

Rather than seeing these plans as evidence of a resurgence of the death penalty, one opponent, Robert Dunham, executive director of the Death Penalty Information Centrer, says the clear brutality of these methods underscores the inherent violence of execution.

"I think that when states start searching for alternatives and the alternatives don't have the peaceful appearance that a successful lethal injection would have, that starts people thinking and I think we are at a critical stage here," he told NPR this week.

Either way the number of death sentences imposed and executions carried out in the US is decreasing.

The number of death sentences imposed last year, 72, was the lowest in 40 years, the New York Times reported last week, while the number of executions, 35, was the lowest since 1994.

So far there have been no reports suggesting that Texas's killing of Sprouse on Thursday did not go smoothly.

"I would like to apologise to the Moreno family and the Steinfeldt family for all of the trouble I have caused them," he said before he died.

"I would like to apologise to my family for all of the trouble that I have caused them. I would also like to thank my family for all of their support. I guess that's it."

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