Looks like the hubby may not have been the only Tsarnaev interested in radical Islamist reading material after all.    A search of Katherine Russell Tsarnaev’s computer turned up data from Inspire, the recruitment magazine published by al-Qaeda online, as well as other material that makes her more interesting than an average witness:

Federal law enforcement officials are sharpening their focus on the widow of the dead suspect in the Boston Marathon bombings 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, the 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 the Tsarnaev brothers hide from authorities, according to the officials, who spoke on the condition of anonymity to discuss the ongoing investigation. …

According to officials, Dzhokhar Tsarnaev also told investigators that he and his brother built the bombs in Tamerlan Tsarnaev’s Cambridge apartment, where the elder brother lived with Russell and their daughter. Officials said that Russell called her husband when she saw his photograph on television — following the FBI’s release of the pictures of the suspects — but did not notify authorities.

One of the key questions for investigators is whether the radical Islamist materials on Russell’s computer belonged to her or were downloaded by her husband or someone else.

Earlier, we discovered that Russell Tsarnaev’s DNA and fingerprints didn’t match those found on bomb fragments.  However, Dzhokhar Tsarnaev told investigators that the bombs were made in the apartment where Tamerlan and Katherine live, and Newsday reports that investigators have found residue in the apartment as well:

A bathtub and kitchen sink in the Cambridge apartment of deceased Boston Marathon bombing suspect Tamerlan Tsarnaev tested positive for residue from explosives, corroborating his surviving brother Dzhokhar’s claims that the duo built bombs at the home, a federal law enforcement source said Friday.

The testing was performed by federal explosives experts and the results suggest bombs were either built in the bathroom and kitchen or stored there at some point, the source said.

In other words, the brothers didn’t build the bombs in the carport.  If they used the bathtub or kitchen sink, it’s a little difficult for the wife to claim ignorance of that effort, although with her work schedule, it’s very possible that she wasn’t around for the assembly itself.  Presumably, though, she would have been suspicious to find the two men scrubbing the sink and bathtub in her absence.

The same could also be said about the computer, too — that Tamerlan and Dzhokhar used it without her knowledge, and that she’s as surprised as anyone to find al-Qaeda propaganda on it.  Dzhokhar got rid of his own laptop, though, and and if Tamerlan was looking to evade suspicion, he probably would have done the same with his own computer.  Perhaps the FBI will be able to determine who used the computer at the time the material was accessed, perhaps not, but their sudden “focus” is hardly surprising.  Many wondered how a young wife with a small child could have her husband go on walkabout for six months and take it in stride, too.

Police and the FBI spent the day scouring the woods, apparently looking for the Tsarnaev’s testing grounds for their bomb designs:

Information about the residue came to light as federal, state and local authorities launched a massive search effort in a wooded area and other locations near the University of Massachusetts-Dartmouth campus for evidence related to the Boston Marathon bombings case, according to the source.

Authorities were scouring the woods after receiving information that evidence linked to the case may have been left there, the source said.

The searches were confirmed by the Massachusetts U.S. attorney’s office.

Federal agents have received information that students heard explosions in the wooded area about a month ago, sparking concerns among investigators that the area may have been used as a testing grounds for the pressure cooker bombs that killed three people and injured more than 260 at the Boston Marathon.

This is another nagging question, one related to Tamerlan’s travels.  Budding bombmakers require lots of practice, and if he wasn’t getting that in Boston, then the assumption could be made that he got it in Dagestan.