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.

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. Tsarnaev’s sentencing hearing is scheduled for Wednesday morning in U.S. District Court.

Among those expected to speak are Rebekah Gregory, a Texas woman who lost a leg in the bombings, and Liz Norden, the mother of two Massachusetts men who each lost a leg.

Tsarnaev, 21, also will be given a chance to speak if he chooses.

Tsarnaev was convicted of 30 federal charges for planning and carrying out the terror attack with his older brother, Tamerlan. Days after the bombings, in the midst of a massive manhunt, the brothers killed a Massachusetts Institute of Technology police officer and engaged in a wild gun battle with police in the Boston suburb of Watertown. Tamerlan died after being shot by police and run over by Dzhokhar as the younger brother escaped in a stolen car.

Tsarnaev’s lawyers admitted he participated in the bombings, but argued that Tamerlan was the driving force behind the attack.

In a note he scrawled in a boat he was found hiding in, Dzhokhar Tsarnaev said the attack was meant to retaliate against the U.S. for its actions in Muslim countries.