(BOSTON) — This week federal authorities charged three of Dzokhar Tsarnaev’s friends with trying to help the surviving marathon bomb suspect by removing his laptop and backpack from his dorm room. Now they’re focused on the older brother’s widow.
Dzokhar Tsarnaev allegedly told investigators he and his brother Tamerlan assembled the bombs in the apartment Tamerlan shared with his wife Katherine Russell and the couple’s young daughter.
Authorities want to know what, if anything, Russell knew about the devices her brother-in-law told the FBI were assembled in her home.
The FBI is also interested in a phone conversation between Tsarnaev and his wife hours after his photograph was released to the public.
Russell worked long hours outside the home and her attorney has said she was shocked at the attack.
On Friday the FBI returned to areas near where the surviving marathon bomb suspect went to school.
Investigators searched four spots in Dartmouth, Mass., where police had received reports of noises a few months ago. Authorities were hoping to find potential places where the marathon bombs were tested, but nothing turned up.
Copyright 2013 ABC News Radio
Seth Fiegerman, CNN
Erin McClam, CNN