Robel Phillipos (left), a college friend of Boston Marathon bombing suspect Dzhokhar Tsarnaev, departs federal court on Monday. Phillipos was found guilty Tuesday of two counts of lying to the FBI. Steven Senne/AP hide caption

itoggle caption Steven Senne/AP

Boston bombings suspect Dzhokhar Tsarnaev on April 19, 2013, as he emerged from a boat stored in a Watertown, Mass., backyard. The red dot of a police sharpshooter's laser sight can be seen on his forehead. Mass. State Police Sgt. Sean Murphy/Boston Magazine hide caption

itoggle caption Mass. State Police Sgt. Sean Murphy/Boston Magazine

Tamerlan Tsarnaev, as seen in a video taken on April 15 near the finish line of the Boston Marathon. FBI.gov hide caption

itoggle caption FBI.gov

April 20 in Watertown, Mass.: Investigators work in and around the boat in which Boston bombings suspect Dzhokhar Tsarnaev was found hiding. Darren McCollester/Getty Images hide caption

itoggle caption Darren McCollester/Getty Images

Some of the graves at the Al-Barzakh Islamic Cemetery in Doswell, Va., where the body of Boston Marathon bombings suspect Tamerlan Tsarnaev has been buried. His grave was not identified to journalists. Yuri Gripas /Reuters /Landov hide caption

itoggle caption Yuri Gripas /Reuters /Landov

FBI Special Agent in Charge Richard DesLauriers (at the microphones), Boston Police Commissioner Edward Davis (standing, at far left) and other authorities briefing the news media on April 19. That's the day Boston bombings suspect Tamerlan Tsarnaev was killed and his brother, Dzhokhar, was captured. Neal Hamberg /Reuters /Landov hide caption

itoggle caption Neal Hamberg /Reuters /Landov

Tamerlan Tsarnaev, as seen in a video taken on April 15 near the finish line of the Boston Marathon. FBI.gov hide caption

itoggle caption FBI.gov

This image from a surveillance video, taken near the finish line of the Boston Marathon, helped investigators identify Tamerlan Tsarnaev (in black cap) and his brother, Dzhokhar (in white cap), as the main suspects in the bombings. FBI.gov hide caption

itoggle caption FBI.gov