Who is Truman Alpers from Revolution and what is their importance?

Truman Alpers is Andi's little brother. When he was ten, he and Andi were walking to school when a friend of Andi's asked her to skip class and spend the day with him. Andi accepts the boy's offer and sends Truman to school alone. While passing a welfare hotel, Truman was taken hostage by a mentally disturbed man, who did not want to leave the hotel. The mentally ill man panicked when a cop pulled his gun, walking into the street, which resulted in the pair being hit by a delivery van. Andi feels tremendous guilt over her brother's death.