The inmate was given a new cocktail of drugs but it all went wrong and he was left twitching in agony until he died of a massive heart attack.

NewsOK reported that the 43-year-old grimaced and tensed his body before his execution was shielded from the press.

It reported that after being declared unconscious 10 minutes in, Lockett spoke at three separate moments. The first two were inaudible, however the third time he spoke, he said the word “man.”

Oklahoma Department of Corrections Director Robert Patton soon halted the execution and later announced that there was a vein failure which meant the “drugs were not having the effect” .

Lockett was sentenced to death for shooting 19-year-old Stephanie Neiman in 1999 and watching friends bury her alive.

Under the US Constitution punishment can be neither cruel nor unusual. 

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