Peter Allen spoke to Nazir Afzal. He's just stood down as one of the country's chief prosecutors. He's been involved in some of the UK's biggest criminal cases of recent times, including the conviction of 9 Asian men for the sexual abuse of 47 young girls in Rochdale, and the prosecution of Stuart Hall on sex offences. Peter asked him about those cases - and also about his fears of a so called "Easter Exodus" as pupils who may have been radicalised head for Syria to fight for ISIS..