Katherine Russell, the widow of slain Boston Marathon bombing suspect Tamerlan Tsarnaev, has hired a criminal lawyer as she faces continued questioning from federal authorities. Investigators are concerned Russell may have had foreknowledge of the Boston Marathon bombings carried out by Tsarnaev and his younger brother, Dzhokhar.

According to the Associated Press, Russell, 24, hired a criminal lawyer on Monday in light of further questioning from federal authorities about her possible connection to the bombings. The lawyer, New York-based Joshua Dratel, has experience defending clients in terrorism cases.

Ever since news of Tsarnaev’s involvement in the bombings was first reported, Russell has been represented by two Rhode Island malpractice lawyers. Dratel becomes the third member of her legal team. The other lawyers, Amato DeLuca and Miriam Weizenbaum, typically specialize in civil lawsuits relating to personal injury. 

The lawyers stated to NBC that Dratel is joining Russell's legal team to make sure "that Katie can assist in the ongoing investigation in the most constructive way possible."

As the Associated Press reports, Russell has been under constant surveilence from federal authorities about any possible foreknowledge she may have had of her husband and brother-in-law’s plot to bomb the Boston Marathon.

NBC also reports that Dzhokhar Tsarnev has told investigators that Russell had no knowledge of the April 15 bombings and was not connected to the plot. He is currently in a Boston-area hospital while being held under high security.

While Russell is currently under close surveillance for her possible knowledge of the Tsarnaevs' plan to bomb the Boston Marathon finish line, there several possibilities that authorities have already ruled out. Last week, the New York Times reported that unknown female DNA found on remains of the pressure-cooker bombs used by Tsarnaev did not belong to Russell. 

Russell met Tsarnaev in 2009, and soon after, she converted to Islam for him. When Russell and Tsarnaev became engaged, she dropped out of college and worked from home as a health aide. The couple had a daughter together. Currently, Russell is living in Rhode Island with her family. 

Russell’s husband was killed on April 19 after a gun battle with police.