Mark Steven Domingo, 26, of Reseda, a former U.S. Army infantryman with combat experience in Afghanistan, faces federal charges. It is alleged that he expressed support for violent jihad, a desire to seek retribution for attacks against Muslims and a willingness to become a martyr. He was, the authorities allege, developing a terrorist plot in which he planned to detonate an improvised explosive device (IED) for the purpose of causing mass casualties.