Looking back, what does the last surviving prosecutor at the Nazi trials think they achieved? Zeinab Badawi speaks to 98-year-old Ben Ferencz in Florida about the nature of evil.

Looking back, what does the last surviving prosecutor at the Nazi Nuremberg trials think they achieved? 98-year-old Ben Ferencz helped liberate the death camps in Europe when he was serving in the US military. Himself a Jew from central Europe, he speaks to Zeinab Badawi in Florida about what he has learnt in his long life about the nature of evil.