Feds Focus on Tamerlan Tsarnaev's Widow

They want to know what she knew

Federal law enforcement officials are sharpening their focus on the widow of the dead suspect in the Boston Marathon bombing after finding al-Qaeda's Inspire magazine and other radical Islamist material on her computer, according to law enforcement officials.

The probe of the computer belonging to Katherine Russell, 24, widow of Tamerlan Tsarnaev, is part of the effort by investigators to determine whether Russell knew anything about the April 15 bombing plot or helped her husband and his brother, Dzhokhar, hide from authorities, according to the officials, who spoke on the condition of anonymity to discuss the ongoing investigation.

Officials have concluded that fingerprints and female DNA found on fragments of the pressure-cooker bombs do not match Russell's, but they say they are continuing to investigate.