BAGHDAD—Bone by bone, workers at the Baghdad morgue are piecing together the victims of Islamic State, a gruesome jigsaw puzzle that has overwhelmed Iraqi authorities and delayed a sense of closure for families of the missing.
After decades of conflict, culminating in Islamic State’s brutal three-year reign over the country’s north, Iraq has one of the highest number of missing people—and unidentified bodies—anywhere. Yet only 25 people in the country have been trained in scientific exhumation techniques, and the morgue attached...