When Syrian authorities recently captured Amjad Youssef, also known as the “Butcher of Tadamon,” residents of the Damascus suburb celebrated in the streets. Few could doubt his complicity in war crimes because at least some of his horrors were captured on video. In several gruesome sequences, shot by the perpetrators in 2013, Youssef and others are seen herding 41 bound and blindfolded civilians, including seven women, to a pre-dug pit lined with tires. There they execute their captives. When