ABC NEWS -- Ibragim Todashev, an Orlando, Fla., associate of one of the Boston bombing suspects, was not armed when he was involved an alleged violent confrontation with an FBI agent that resulted in Todashev being shot to death in his apartment, law enforcement sources told ABC News.
The FBI, along with two members of the Massachusetts State Police, was interviewing Todashev during the early morning hours of May 22 when the alleged confrontation took place.
Officials initially told ABC News and other news outlets that a knife was involved in the confrontation.
However, by the day after the shooting, officials noted there was confusion about whether a weapon was involved.
The investigation so far is showing there was an abrupt change in Todashev's demeanor and a physical confrontation ensued, sources said.
A samurai sword was in the room, which may have accounted for some of the initial confusion over whether a weapon was involved, sources added.
Todashev was a trained mixed martial arts fighter. The FBI agent sustained non-life-threatening injuries in the incident.
Just before the deadly confrontation took place, Todashev, law enforcement source said, allegedly was preparing to sign a statement confessing his involvement in a 2011 triple murder in Massachusetts.
Boston bomber Tamerlan Tsarnaev is also a suspect in that cases, sources said.
The FBI tonight issued the following statement regarding its internal review of the use of deadly force in this incident:
"The FBI is conducting a review of the May 22, 2013 shooting of Ibragim Todashev, 27, which occurred at Todashev's residence, at 6022 Peregrine Avenue, Orlando, Fla. The FBI's shooting incident review team interviews witnesses and gathers information regarding the shooting incident for presentation to a Shooting Incident Review Group (SIRG), which consists of members from the FBI and the Department of Justice. The SIRG examines all of the information and determines the reasonableness of the application of deadly force in accordance with the Department of Justice's Deadly Force Policy and the law. While this internal review process is occurring, we cannot comment regarding investigative details.
"The FBI takes very seriously any shooting incidents involving our agents and as such we have an effective, time-tested process for addressing them internally. The review process is thorough and objective and conducted as expeditiously as possible under the circumstances."