Man shot during Boston probe was 'on verge of confession'
A Chechen immigrant shot and killed during a violent confrontation with Boston Marathon bombing investigators was about to confess to other killings, officials have told US media.
Ibragim Todashev reportedly admitted a role in a triple murder near Boston in September 2011 and implicated bombing suspect Tamerlan Tsarnaev in the crime.
Todashev, 27, was shot and killed on Wednesday in Orlando, Florida.
The 15 April Marathon blasts killed three people and injured 264 others.
No evidence has emerged linking Todashev to the bombings.
There are conflicting reports about the events that led to Todashev's death in the early hours of Wednesday.
Todashev was "about to sign a statement" admitting to involvement in the killings when he suddenly "went crazy", officials told ABC News.
Three anonymous law enforcement officials told the Associated Press news agency Todashev was shot after attacking the FBI agent with a knife, but two of those officials later said it was no longer clear what had happened.
An FBI agent and two Massachusetts state police officers were also at the Orlando interview.
It focused on the unsolved 2011 incident, in which three men were found dead in a rented property on a quiet, residential street in the town of Waltham.
The men in Waltham were reportedly found with their throats slashed and marijuana sprinkled over their bodies.
But officials in Middlesex County, Massachusetts, have refused to comment on the reports.
US media reported that Todashev had known Tamerlan Tsarnaev, the ethnic Chechen Boston bombing suspect killed in a shootout with police days after the marathon blasts.
Tsarnaev's brother, Dzhokhar Tsarnaev, 19, is being held in a prison hospital after being shot before capture. He faces the death penalty if convicted.
Public records show that Todashev - who was reportedly a mixed-martial arts fighter - lived last year in Watertown, Massachusetts, just outside Boston.
In a statement about Wednesday's shooting, the FBI said investigators had been interviewing Todashev when "a violent confrontation was initiated by the individual".
"During the confrontation, the individual was killed and the agent sustained non-life threatening injuries."
The FBI said an agent had been taken to hospital with non-life-threatening injuries. An agency team was dispatched to review the shooting, standard procedure in such cases.
Police blocked off the apartment block where Todashev was shot.