Katherine Russell `` is doing everything '' to help investigators , lawyer says . Comment: Did one brother brainwash the other ? Tamerlan Tsarnaev was arrested for domestic violence a year before marriage . `` She knew nothing about '' her husband being a suspect , Russell 's lawyer says .
Katherine Russell `` is doing everything '' to help investigators , lawyer says . Comment: Tamerlan Tsarnaev was arrested for domestic violence a year before marriage . `` She knew nothing about '' her husband being a suspect , Russell 's lawyer says .