How Balkan war criminals were hunted down and brought to justice

Former Bosnian Serb leader Radovan Karadzic is the latest perpetrator to be convicted of war crimes committed during the 1990s Balkan wars. In "The Butcher's Trail," author Julian Borger examines how tough it was to hunt down those responsible for the most grotesque atrocities of the conflict. Borger sits down with chief foreign affairs correspondent Margaret Warner.