A death row inmate "gasped and snorted" as he took two hours to die by lethal injection in the latest "botched" execution in America, Reuters reported.
Double killer Wood, 55, was given a lethal injection of drugs at 1.52pm local time but was not pronounced dead until 3.49pm, the Arizona attorney general's office said.
Prior to his execution Wood was one of six death row inmates who sued Arizona arguing secrecy surrounding the drugs used in other botched executions in Ohio and Oklahoma violated their human rights.
His death raises questions about the use of the death penalty in the US.
More top news
Bradley Lowery has a rare form of cancer and although he's having treatment it will only give him more time.
Delivery firms hold out against calls to improve conditions for self-employed workers as Hermes says any such move could cause job losses.
Wet and very windy weather spread in from the west overnight with snow expected across much of southern Scotland.