BARRING a last-minute reprieve, the state of Florida will execute Mark James Asay today, August 24th, using an untested cocktail of drugs. Mr Asay is a white supremacist who murdered two men in Jacksonville in 1987. This will be the state’s first execution in 18 months. In recent years efforts by pharmaceutical firms and international distributors to restrict the supply of drugs that could be used in American executions have caused departments of corrections to look for alternative options. As a result, many experts are concerned that Mr Asay will be conscious throughout the procedure and can be expected to suffer severe pain. How did America’s system of capital punishment come to be so inhumane?

Execution by lethal injection in America can be traced to 1977, when a forensic pathologist named Jay Chapman proposed that death-row inmates be killed using a mixture of three drugs. This method was seen as being a kinder than using the electric chair or a firing squad says Maya Foa, the director of Reprieve, a human-rights charity. The first drug was sodium thiopental (a barbiturate that anaesthetises); the second was pancuronium bromide (a paralytic drug); and the third was potassium chloride (a powerful chemical that stops the heart). This cocktail is administered in sequence via intravenous lines, with an inmate strapped to a gurney and sometimes covered with a sheet.

Similar combinations of anaesthetic, paralytic and lethal drugs have been used in America ever since. They are also used by China, which executes the largest numbers of prisoners every year. Rendering prisoners unconscious as the first step is meant to spare them extreme pain brought on by the lethal drug. One of the biggest problems with this three-drug regimen (whichever individual drugs are used) is that it is technically challenging to anaesthetise correctly. In hospitals, this task is usually done by highly trained medical staff (drawn from a profession that largely refuses to assist in the killing of prisoners). When non-medical staff from departments of corrections attempt to use the three-drug cocktail, the results are often disastrous, leading to horrifically botched executions. It is thought that over the years many prisoners have been executed while still conscious and in great pain—but unable to cry out because they have been paralysed by the second drug in the sequence.

Around 2010, problems with the supply of sodium thiopental in America led state governments to look for suppliers abroad. But strong moral objections to capital punishment overseas led to the introduction of export controls on drugs that might be used for executions in America. By 2013, prisons were experimenting with different drugs. Some states may have violated distribution controls in order to obtain the drugs they need. Florida has been quietly stockpiling a short-acting anaesthetic agent called etomidate, a generic drug available from a number of manufacturers in America. Its sale is unrestricted. Mr Asay will be the first person to receive it as part of an execution. Anaesthesiologists have pointed out that it may not render him fully unconscious and is likely to cause a huge amount of pain on injection. Moreover, the prison has been unable to get hold of potassium chloride, and will use potassium acetate instead. This drug has been employed in an execution only once, in Oklahoma, when it was used by accident.