According to the filings, Todashev told investigators Tamerlan Tsarnaev participated in a triple slaying in Waltham on Sept. 11, 2011.
In that case, three men were found in an apartment with their necks slit and their bodies reportedly covered with marijuana. One of the victims was a boxer and friend of Tamerlan Tsarnaev.
The filing was prosecutors’ attempt to block Dzhokhar Tsarnaev from getting certain information from authorities, including investigative documents associated with the Waltham slayings.
Authorities allege that Dzhokhar Tsarnaev, 20, and 26-year-old Tamerlan Tsarnaev, ethnic Chechens from Russia, planned and carried out the twin bombings near the finish of the marathon on April 15. Three people were killed and more than 260 were injured.
Dzhokhar Tsarnaev faces 30 federal charges, including using a weapon of mass destruction and 16 other charges that carry the possibility of the death penalty.
Tamerlan Tsarnaev died in a gunbattle with police as authorities closed in on the brothers several days after the bombings.
Shootings by FBI agents are almost never deemed unjustified, and the internal investigations into those shootings are typically not reviewed by outside agencies, said Samuel Walker, a criminal justice professor at the University of Nebraska at Omaha who specializes in police accountability and use of force. Walker pointed to FBI documents obtained by The New York Times under a Freedom of Information Act request last year showing that no FBI agents were found at fault in about 150 shootings between 1993 and 2011.
Most major police departments have several layers of review of officer shootings to improve tactics, training and policies, Walker said.
“It is my opinion that the FBI is still an insular organization. It’s not part of the municipal police. There has been some real progress there in terms of post-incident review in shootings. That’s what doesn’t happen with the FBI, and that’s what I think needs to happen,” he said. “The FBI is not a part of that world. They think they’re better, they are above that.”