Gaelscoil Choláiste Mhuire primary school is on Parnell Square in north Dublin, near the busy thoroughfare of O’Connell Street. At 1:30 p.m. on Nov. 23, the children were lining up to join the after-school club when a 49-year-old man attacked them and their teachers with a knife. He stabbed two 5-year-olds and a 6-year-old, critically injuring one of the 5-year-olds, and severely wounding Leanne Flynn Keogh, an after-school teacher, as she shielded the children.

As school staff and passersby struggled with the knifeman, a passing Deliveroo driver laid him out with his motorcycle helmet. “I just hit him in the head with all power I have, and he fell down,” said Caio Benicio, who came to Ireland a year ago from Brazil. The police took the attacker to a nearby hospital, where the doctors placed him in an induced coma. He woke up on Dec. 5. By then, Dublin had seen the worst outbreak of rioting in recent Irish history.