The drugs used in a botched lethal injection in Oklahoma were the subject of an appeal from lawyers representing two death row inmates.
The execution of Clayton Lockett was stopped after the drugs he was administered "weren't working as designed", prison officials said.
Lawyers for Lockett and fellow inmate Charles Warner had argued before the botched execution that the use of an untested cocktail of drugs could subject their clients to "cruel and unusual punishment", which is prohibited by the US constitution.
More top news
A British citizen was likely taken to China against his will in a 'serious breach' of a bilateral agreement with the UK, a report says.
Atheist Richard Dawkins has cancelled his Australia and New Zealand tour after suffering from a 'minor stroke', his management said.
Sleet and snow for some parts of Scotland. Elsewhere in the UK will be cold, cloudy and with some showers.