Hearing your child has been involved in a mass shooting must be one of the worst things a mother can ever hear.
But imagine if that pain is amplified by horror when you find out it is your child that carried out those attacks on innocent children.
This is what happened to Terri Roberts when she received a call at work from her husband telling her to come to their son Charlie’s house in October 2006.
On her way she heard on the radio that there had been a shooting a nearby school and several Amish children were dead.
When she arrived at her son’s home in Pilkington, Pennsylvania, a police officer said her son had walked into the schoolroom, ordered the boys outside, and shot 10 young girls before turning the gun on himself.
Two were killed and another five were injured - including six-year-old Rosanna King who suffered severe brain injuries.
Speaking to the Guardian ahead of the publishing of her memoir, Ms Roberts recounts the days and weeks that followed as she combed through every aspect of her son’s life wondering what she missed.
She wrote in the book: "I was – always will be – his mother. Surely if anyone could spot signs of trouble it would be the woman who gave birth to him. At what point did bitterness begin to seethe beneath the surface contentment? Or hate tug harder at the mind and heart than love?"
She said she was amazed by the Amish community who not only forgave her family - which included her son’s wife Marie and three young daughters - but also rallied around to protect them from the press at Charlie’s funeral.
Two months later Ms Roberts reached out to Rosanna’s parents and was invited to meet her at their home.
She found out they could not eat together as a family anymore because Rosanna needed to supervised at all times. She started volunteering to sit with her while the family ate.
Today Rosanna - who is now 16 - has become "almost like a granddaughter".
Forgiven: The Amish School Shooting, a Mother's Love and a Story of Remarkable Grace by Terri Roberts is out now
