On Thursday the parents of Katherine Russell, the widow of Tamerlan Tsarnaev, gave testimony to a federal grand jury in Boston. The appearance has been confirmed both by her attorney and the family’s attorney.

Why is a grand jury still taking testimony? Russell’s attorney Joshua Dratel says he has been assured that she is not a target of the investigation. Three teenage friends of Dzhokhar Tsarnaev have already been indicted because they acted on a suggestion from him after one sent him a text message saying the picture of a bomber on TV looked like him and he replied to the effect of lol, you can have the stuff in my room then. Who else is there, his roommate? The Russells are not likely to even know him.

I welcome a procedural explanation from you legal experts out there, but until it or some better theory arrives my hypothesis is this. The government is well aware that its central accusation against Dzhokhar Tsarnaev, that he caused the second of the two explosions at the Boston marathon on April 15, rests on faulty evidence. (The fact that the evidence is faulty has been shown on serious websites such as WhoWhatWhy and Woody Box’s blog, as noted in previous FDL posts by lauraw and myself, and cannot be dismissed as the product of the imagination of Alex Jones or the people who deny that the Boston bombing even happened.)

In addition, the government is aware that the agency responsible for presenting its evidence, the Boston office of the FBI, has been unable to give a coherent explanation of why it killed Ibragim Todashev during the course of the investigation of this case. This point is well known, and would not help the government in any related matter such as the prosecution of Tsarnaev.

Therefore I surmise that the government is using the grand jury to see if it can find anything that could give rise to indictment of Tsarnaev on more peripheral charges than are already in the existing indictment, say, conspiracy to commit something not yet mentioned. I surmise that it is doing this in the hope that it can get something to stick in the event that it is unable to obtain a successful result in plea negotiations and is forced to go to trial.