(Updates with details from prosecutor's report)
By Barbara Liston
ORLANDO, Fla., March 25 (Reuters) - A U.S. federal agent who fired six to eight gunshots and killed a man being questioned about his connection to a 2013 Boston Marathon bombing suspect will not face state criminal charges, a Florida prosecutor said on Tuesday.
The Federal Bureau of Investigation agent's actions were justified to defend himself and a Massachusetts state police officer after the man threatened them in his Orlando apartment in May 2013, State Attorney Jeff Ashton concluded.
"A complete review of the investigation leads me to conclude that criminal charges against the special agent of the FBI are not warranted," Ashton wrote in a letter to FBI Director James Comey.
Ashton's findings echoed the FBI's account of the shooting death of Chechen immigrant Ibragim Todashev, 27, who the agency said suddenly attacked and injured an FBI agent during the interrogation.
Todashev was an acquaintance of Tamerlan Tsarnaev, one of two Chechen brothers accused of carrying out the Boston bombings that killed three people and wounded more than 260.
At the time of his death, Todashev was being questioned about his suspected involvement in a triple murder in September 2011 in Massachusetts that law enforcement officials believed was linked to Tsarnaev.
Ashton said Todashev was writing a statement about the triple murder after a long interview with law enforcement officers when he flipped a coffee table, striking the agent in the head and causing him to fall to the ground bleeding.
Todashev ran to the kitchen while the agent and police officer pulled their weapons as the man returned holding what they described as a "pole" over his head.
The FBI agent shot Todashev three to four times as he approached the police officer, according to Ashton. Todashev dropped to his knees, then sprang toward the officer in a low-angled lunge. The agent fired three or four shots, killing Todashev, Ashton said.
The prosecutor said the entry angle of the bullets alleviated his concern about Todashev being shot in the back because it confirmed the account by the police officer, who had not seen the autopsy.
Ashton said there was no evidence the agent, who was aware of Todashev's training in mixed martial arts, acted with malice or committed intentional misconduct.
U.S. prosecutors also cleared the agent of wrongdoing in findings released on Tuesday.
The Florida prosecutor's report did not exonerate the agents "of any negligence or wrongdoing on their part which could have avoided the death of a suspect in questioning," said the leader of a Muslim civil liberties group.
"The prosecutor's review was limited to a very narrow review of whether the officer was justified to use lethal force during the seconds he pulled the trigger," said Hassan Shibly, executive director of the Tampa-based branch of the Council on American-Islamic Relations (CAIR).
The FBI account of the shooting has been questioned by Todashev's father, who said his son was unarmed.
Shibly has said his organization's independent review concluded that Todashev, who was in the United States legally, was shot seven times and received a major wound, possibly a bullet hole, to the back of the head.
The CAIR investigation also found blood splatter and other physical damage at the scene that pointed to Todashev being shot while he was lying on the ground, Shibly said.
Tamerlan Tsarnaev, 26, died on April 18, 2013, after a gunfight with police several days after the April 15 bombing attack, while he and brother Dzhokhar, now 20, were trying to flee the city. The younger Tsarnaev was wounded and later arrested and is awaiting trial on charges that could result in the death penalty if he is convicted. (Editing by Colleen Jenkins, editing by G Crosse)