Internationally acclaimed British documentary maker Dan Reed is best known for his “Terror Trilogy” for HBO: three films that explore high-profile urban terrorist sieges, including a theatre in Moscow, luxury hotels and a Chabad centre in Mumbai, and now a shopping mall in Nairobi. Dan Reed was in Seattle to present his documentary “Terror at the Mall: The Nairobi Siege” at SIFF Cinema as part of the Seattle International Film Festival’s continuing series of free screenings of HBO documentaries.