Westgate attack: BBC uncovers new evidence
3 October 2013 Last updated at 15:43 BST
A BBC investigation has uncovered evidence of a breakdown in control when the military entered the Westgate mall, Nairobi, during an attack by al-Shabab militants.
Meanwhile, a leaked security document has revealed the group behind the attack recruited members not just abroad, but from within Kenya itself.
Karen Allen reports from Nairobi.