Boston bomber friend shot dead by FBI The FBI said that Mr Todashev was being "interviewed in connection with the Boston Marathon bombing investigation" when he lashed out, inflicting "non-life threatening injuries" on the agent. Two law enforcement sources also told The Boston Globe that he was suspected of being involved in an unsolved triple-murder in September 2011, to which Tamerlan Tsarnaev has also been linked. The three victims were found in the Boston suburb of Waltham with their throats slashed and covered in marijuana. One victim, 25-year-old Brendan Mess, was once the best friend of Tamerlan Tsarnaev. Mr Todashev was also being questioned by officers from Massachusetts State Police, the force that has been looking anew at the 2011 triple-murder, which took place on September 11. The 27-year-old Chechen, who is said to have been a mixed martial arts enthusiast, reportedly lunged at the FBI agent with a knife during his questioning. Khusen Taramov, a friend, told an Orlando television station that Mr Todashev "was not a radical" and "never had a gun." He was "shocked" by the Boston marathon bombing, the friend said. Mr Taramov said that in recent days Mr Todashev had claimed that he was being "set up" by the FBI due to his link to the late marathon bomber. John Miller, a former FBI assistant director, told CBS News that the agency had been monitoring Mr Todashev since soon after the Tsarnaevs emerged as the prime suspects behind the bombing. "The interest in him was higher because of a couple of factors: He was in contact with Tamerlan Tsarnaev, he had been to Boston to visit him, and he was planning a trip to Chechnya," he said. Mr Miller said that the FBI was prompted to interview Mr Todashev when it appeared that he had cancelled his trip to Chechnya, the war-torn Russian province also said to have been visited by Tamerlan Tsarnaev.