One man, who gave his name as Ignacio Aguirre, described the arrest of his son. He said the boy had been at the beach, where he used a knife to cut a watermelon. He put the knife into a backpack. Several days later, without thinking about it, he took the backpack to school and tripped a metal detector. It was an innocent mistake, the man said, but it resulted in a visit from ICE and house arrest with an ankle bracelet for his child.