Allen Ault: The day I sent a man to the electric chair
13 February 2014 Last updated at 08:32 GMT
Allen Ault was head of corrections in the US state of Georgia in the 1990s. He was responsible for running the machinery of death in a state still committed to the deterrent effect of capital punishment.
He did not just order others to carry out executions, he felt it was his duty to be present at the executions himself. But after watching a handful of the state's most serious criminals being strapped to the electric chair he decided he could stomach no more.
Mr Ault left his post and became a campaigner against the use of capital punishment in the US.
BBC HARDtalk's Stephen Sackur talks to him about what prompted this momentous change of heart and how he is still, years later, haunted by these executions.
This programme forms part of the BBC's special series of programmes devoted to the idea of freedom; how it is achieved and how it is taken away.
You can see the full interview on BBC World News at 09:30, 16:30 and 21:30 GMT on Thursday 13 February 2014 and on BBC News Channel on Friday 14 February at 00:30 and 04:30 GMT.