27-year-old Ibragim Todashev, was taken into custody by the FBI as a person of interest in the Boston Marathon bombings. Reportedly, Todashev became violent during questioning and the agent felt that he was in danger, Todashev was shot and killed.

The victim was reportedly a friend of bombing suspect Tamerlan Tsarnaev and, like Tsarnaev, was also an ethnic Chechen. A mutual friend of the two men told authorities that, "Back when (Todashev) used to live in Boston, they used to hang out -- not hang out -- he knew him. They met a few times because (Todashev) was a MMA fighter and (Tsarnaev) was a boxer. They just knew each other. That's it,"

He added that Todashev last spoke with Tsarnaev via phone or Skype several days before the bombing, but the conversation was short and had nothing to do with the bombings.

The FBI agent, whose name has not been released,  was taken to a hospital with non-life-threatening injuries.