Boko Haram:Terror Unmasked, Part 1: Ruling by Fear

More than 18,000 people have died in Nigeria's seven year conflict with Boko Haram, the terror group known for abducting hundreds of Chibok schoolgirls. A Boko Haram trademark has been its stealth. Now, VOA has obtained a trove of secret videos made by Boko Haram videos that show