Boston Bombing Suspect Wants Access to Investigative Records on Brother's Involvement in Triple Homicide

Argues will help his defense

The surviving Boston Marathon bombing suspect, who faces a potential death penalty, is fighting to get access to investigative records that implicate his dead older brother in a triple slaying in 2011.

In a filing this week in federal court, prosecutors say they have alerted Dzhokhar Tsarnaev (joh-HAHR' tsahr-NEYE'-ehv) that a friend alleges that Tsarnaev's older brother, Tamerlan, participated in the killings.