Ahmed Wali Karzai, the powerful half-brother of Afghan President Hamid Karzai, was shot dead in Kandahar this morning, reportedly by a long-trusted member of his security detail. Karzai  was the provincial chairman of Kandahar, making him the most powerful man in southern Afghanistan. For some time, American military officials believed Karzai to be involved in the Afghan drug trade and government corruption. In 2009, it was revealed that the C.I.A. had been paying Karzai for services including  recruiting  a paramilitary force for the previous eight years. Bilal Sawary, correspondent for the BBC, has the latest from Kabul.