BOSTON — More than 30 victims of the Boston Marathon bombing and their family members are expected to describe the attack’s impact on their lives before a judge formally sentences bomber Dzhokhar Tsarnaev to death Wednesday.

In May, a federal jury condemned Tsarnaev to die for bombing the 2013 marathon with his brother. Three people were killed and more than 260 were injured when the brothers detonated two pressure-cooker bombs near the finish line.

Under the federal death penalty law, Judge George O’Toole Jr. is required to impose the jury’s sentence.