An FBI agent has shot dead a suspect who turned violent while being questioned about the Boston marathon bombing.
The agent and two police officers were interviewing 27-year-old Ibragim Todashev, a mixed martial arts fighter, at his house in Orlando, Florida. The FBI said the agent acted on an imminent threat and opened fire. The agent was taken to a hospital with minor injuries.
Khusn Taramiv, a friend of Todashev, said that Todashev had known one of the Boston Marathon bombing suspects, Tamerlan Tsarnaev, from martial arts fighting. Todashev also lived in Watertown, Massachusetts, just outside Boston, last year.
The FBI gave no details on what investigators had hoped to learn from Todashev.
The authorities "were talking to us, both of us, right?" Mr Taramiv said. "And they said they need him for a little more, for a couple more hours, and I left, and they told me they're going to bring him back. They never brought him back."
Tamerlan Tsarnaev was killed in a shootout with police days after the April 15 bombings. His brother, Dzhokhar, survived and is charged with carrying out the attacks that killed three and wounded more than 260.
An FBI team was dispatched from Washington to review the shooting, a standard step in such cases.
Todashev was arrested earlier this month on a charge of aggravated battery after getting into a fight over a parking spot with two men - a father and son - at an Orlando shopping mall. The son had a split upper lip and several teeth knocked out.
"Also by his own admission Todashev was recently a former mixed martial arts fighter," one of the officers who arrested him said in his report. "This skill puts his fighting ability way above that of a normal person."
Todashev was released on bail after the attack.