<<Mortara eventually became a priest and fled Rome rather than return to his family. He died in an abbey in Belgium in 1940.>>
Allow me to comment on the last two sentences. By most accounts I've seen, Edgardo Mortara lived out his life as a Catholic priest, effective and apparently happy in his ministry. He seems to have had at least a partial reconciliation with his mother. To the extent that he lived a good and happy life, I think we can be happy for him.
But none of that diminishes the significance of the radically evil act of kidnapping him and removing him from his home and family at the age of six. Had he chosen to abandon his family, his culture and his religion at the age of twenty-six, or maybe even at sixteen, we could affirm his right to make that decision and rejoice with him if it brought him joy. However, snatching him from his family, culture and religion when he was six was an indefensible act of violence; we must not affirm it, rationalize it, excuse it, or forget it.