Many of today’s scripted horror movies are built around the concept of “found footage” – of framing their drama, visually and narratively, from the point of view of hand-held and surveillance cameras. This new documentary does the same thing, but this is no trick, and the horror in this hour-long program is that the violence is all too real. British filmmaker Dan Reed assembled Terror at the Mall using surviving footage from hundreds of surveillance cameras, still photos, cellphone video, and by interviewing survivors about their ordeal. The event in question took place last year in an upscale shopping mall in Nairobi, Kenya, when four young men from the Shabab militant group invaded the mall, sporting automatic weapons and killing almost everyone in their path – more than 60 by the time the siege was over. But the cameras, and this documentary, also show acts of amazing heroism and ingenuity, as some of those people trapped in the mall find ways to survive, while others try to enter the mall in hopes of saving them. It’s as captivating and haunting as any scripted drama I’ve seen all year – and stays with you long afterward.