Tony decided to kill his little brother the day he found out their mother would only be able to afford empathy overlays for one of them.
His own empathy wasn't chemically numbed: what most adults found necessary for psychological survival was considered illegal for children below sixteen. He wasn't a natural either. He simply understood the concept of neurochemical budgets with the inarticulate precision of somebody born in a world of empty stares, so that same night he put poison in their favorite food and gave his little brother his spoon.
The funeral was as short and matter-of-fact as everyone else's. It was only the next night that Tony noticed the old way his mom looked at his brother's empty chair and the new way she looked at him as she was serving him his favorite food.
Tony picked his spoon.