A full review has been ordered into the execution of double murderer Joseph Wood, who took two hours to die after being given a lethal injection.
Arizona's Governor Jan Brewer said that while justice had been done she was concerned by how long the lethal injection procedure took.
She said: "One thing is certain, however, inmate Wood died in a lawful manner and by eyewitness and medical accounts he did not suffer.
"This is in stark comparison to the gruesome, vicious suffering that he inflicted on his two victims, and the lifetime of suffering he has caused their family."
More top news
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.
At least 52 people have been killed after a fight broke out between two rival drugs gangs in a Mexico prison.