The agent and two Massachusetts State Police troopers were interviewing 27-year-old Ibragim Todashev, a mixed martial arts fighter, at his townhouse early Wednesday in Orlando. In a statement, the FBI said the agent acted on an imminent threat and opened fire. The agent was taken to a hospital with injuries that were not life-threatening.
Khusn Taramiv, who described himself as a friend of Todashev, told Orlando TV station WESH that Todashev had known one of the Boston Marathon bombing suspects, Tamerlan Tsarnaev, from mixed martial arts fighting. Public records also show Todashev lived in Watertown, Mass., 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?" 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 was hospitalized with a split upper lip and several teeth knocked out, according to a report from the Orange County Sheriff's Office.
"Also by his own admission Todashev was recently a former mixed martial arts fighter," the arresting deputy said in his report. "This skill puts his fighting ability way above that of a normal person."
Todashev was released on $3,500 bail after his May 4 arrest. His attorney, Alain Rivas, didn't immediately respond to a call for comment Wednesday.
Police tape blocked off the complex of townhomes near Universal Studios where Todashev was shot.
Associated Press writers Pete Yost in Washington and Mike Schneider in Orlando contributed to this report.