Kate Adie introduces correspondents' stories from around the world: This week: After the killing of 20 hostages at an upmarket café in Bangladesh Sanjoy Majumder hears how it is the backgrounds of the killers that is worrying people in Dhaka. Linda Pressly meets the people attending an unusual rehab centre for alcoholics in Canada. Martin Patience tries in vain to get an accident report for a prang in his car in Nigeria. Shile Khumalo looks at how the Oscar Pistorius murder trial is being seen as an example of lingering white privilege in the South African Justice system. And Tony Vale is on the hunt of avocado rustlers in New Zealand.