New York: Investigators have discovered radical Islamic materials and an al Qaeda magazine on the computer of Boston Marathon bomber Tamerlan Tsarnaev`s widow, and have also found explosive residue throughout their house.
The files found on Katherine Russell`s hard drive are part of an investigation into whether the woman - who claimed to be in the dark on her husband`s terrorist activities - was aware of his plan to set off the two bombs, reports the New York Post.
It wasn`t clear whether the files belonged to Russell, 24, or Tamerlan, 26.
The explosive residue was found on the kitchen sink and table and in the bathtub at their home in Cambridge, Mass.
The surviving bomber, Tsarnaev`s brother, Dzhokhar, told investigators they built the bombs in Tamerlan`s basement.
Officials said female DNA and fingerprints on a piece of pressure cooker found in the explosive debris did not match Russell`s.
Also, posters in support of Dzhokhar have reportedly sprung up on walls in Chechnya.
The posters declare the terror suspect "not guilty" and ask for donations to pay his medical and legal bills.
Pro-Tsarnaev leaflets have also spotted in the Kyrgyzstan capital of Bishkek.