The trial has begun of a former navy captain known as the “Blond Angel of Death” over his alleged crimes against humanity.Alfredo Astiz, 57, whose nickname came from his cherubic looks in the 1970s, is charged with the killing of two French nuns and the disappearance of an Argentine journalist. Sixteen other former police and military officers are also accused of playing a role during the country’s “dirty war” against leftist dissidents. Astiz and the other men on trial worked in task forces at the Naval Mechanics School, or ESMA, where thousands of people died or went missing during the military dictatorship. Witnesses claim one of the nuns, Leonie Duquet, was imprisoned at ESMA before her body was tossed from a plane into the Atlantic Ocean on one of many “flights of death” meant to permanently dispose of prisoners’ bodies. Astiz has been tried before in 1985 but amnesty laws halted the proceedings.