Killer dies of heart attack after twenty minutes of agony when Oklahoma experimental drug execution goes wrong. Second lethal injection postponed

The execution of Clayton Lockett was halted about 20 minutes after the first of three experimental drugs was administered

He received the entire cocktail of injections - which had never been tried in Oklahoma before - but for some reason the drugs didn't kill him

Some 14 minutes into the execution, Lockett sat up and said 'something's wrong' but the prison officials only lowered the blinds in the execution chamber

The inmate finally suffered a massive heart attack and died at 7.06p.m.

Lockett was sentenced to death for shooting a 19-year-old Perry woman and watching his friends bury her alive

Earlier Tuesday, he was refused his last meal because it exceeded the $15 price limit

READ MORE: http://www.dailymail.co.uk/news/article-2615631/Oklahoma-prepares-execute-2-inmates.html