Seventy years ago, Ben Ferencz became the chief prosecutor of 22 commanders of the Einsatzgruppen Nazi death squads at trial number 9 at Nuremberg. Now 97 years old, he's the last Nuremberg prosecutor alive today.

And the images he saw during the Holocaust are still vivid in his mind.  

"I'm still churning," Ben Ferencz says, nearly in tears, in an interview with correspondent Lesley Stahl this week on 60 Minutes.