ORLANDO, Fla. — One of the lingering mysteries of the Boston Marathon bombing involves the grisly triple slaying that preceded it.
On the night of Sept. 11, 2011, three men had their throats slashed in the quiet suburb of Waltham, Mass. One victim had been a good friend of Tamerlan Tsarnaev, one of two chief suspects in the deadly explosions near the marathon finish line before he was killed in a shootout with police.
After the attack, authorities closed in on Ibragim Todashev, another friend of Tsarnaev, who they believed might implicate both himself and Tsarnaev in the Waltham killings.
Shortly before midnight, after more than four hours of questioning, a Massachusetts state trooper seemed convinced that Todashev, 27, was about to confess to the crime. "Whos your daddy," the trooper said in a text message.
A short time later, Todashev was dead, killed by seven bullets from an FBI agent's gun.
On Tuesday, a Florida prosecutor announced that the agent would not face charges, saying he acted in self-defense after Todashev, a mixed martial arts fighter from the Russian republic of Chechnya, heaved a coffee table at the agent and charged him and a trooper with a long red pole.
"There was no doubt in my mind that Todashev intended to kill both of us," the agent, who was not identified, told investigators.
The report, released by Orlando-area State Atty. Jeffrey Ashton, includes hundreds of pages documenting his investigation, providing a rare window on the sort of inquiry the FBI usually handles in secret. Also on Tuesday, top FBI officials said their internal review had cleared the agent.
The shooting has been a source of controversy for the bureau, which has had a fraught relationship with the Muslim community since the Sept. 11, 2001, terrorist attacks. After Todashev's death, the FBI issued confusing and what appeared to be conflicting accounts of what happened, and even the new report does not explain why the FBI may have suspected Tsarnaev in the Waltham killings.
The local Council on American-Islamic Relations on Tuesday questioned the trustworthiness of the report, saying it "relied on evidence gathered by agents of the same agency involved in his death."
"The only person who can contradict that government's narrative is now dead," said Hassan Shibly, the group's executive director in Florida.
The group also contends that the FBI harassed and intimidated Todashev's friends after he died, accusations the report does not address. Todashev's girlfriend and another friend were deported, and when his best friend visited Russia, he and his brothers were barred from returning to the U.S., council officials say.
The report is unlikely to satisfy Todashev's father, Abdulbaki Todashev, who believes the FBI intentionally killed his son. Todashev had been recovering from knee surgery, his father said, and was not physically capable of lashing out at officers. His attorneys plan to release the results of their own investigation soon.
"They say that time is a doctor. Not in my case," he told The Times this week. "Every morning I wake and every night I go to bed with this sense of gross injustice done to my son and which is still continuing to be done so long after his death at the hands of an FBI agent."
Todashev was known as both a hothead who picked fights and a charmer with a soft spot for children. He moved from Russia to Boston in 2008 on a student visa and told his father how much he loved the U.S. and its numerous gyms devoted to martial arts and boxing.
That was where Todashev and Tsarnaev spent time together. Both were dark-haired, sinewy Chechen immigrants. Both were practicing Muslims. Both spent hours honing their fighting skills. Still, Todashev's family says they were little more than gym buddies.
By the time of the April 15 bombing, Todashev had obtained his green card and was living with his girlfriend in Orlando, home to a fast-growing Muslim population. Todashev prayed regularly, worked odd jobs and dreamed of becoming a professional fighter, though his knee surgery had recently kept him out of the ring.
Within a week of the Boston attack, which killed three people and wounded more than 260 others, an FBI agent based there and two Massachusetts state troopers were asked to investigate possible ties between Tsarnaev and the triple homicide. By this time, Tsarnaev had been killed and his younger brother, Dzhokhar, arrested.
It's unclear why investigators suspected that Todashev may have had a hand in the Waltham killings. Before meeting him, investigators studied videos of his martial arts bouts and pored over police reports. (In May, during a spat over a parking space in Orlando, Todashev had pummeled a man until he was unconscious and missing several teeth.)
"He was a trained fighter," one trooper told state investigators. "He was pretty good at what he did … just the sheer toughness of the individual."
On May 21, as sunlight waned, four law enforcement officers arrived at Todashev's apartment complex near Universal Studios, a cluster of brownish buildings brightened with door wreaths and children's bikes. One officer stayed outside, and the others planned to confront Todashev with forensic evidence from the triple homicide.
Todashev's apartment, as described in the report, was dark and cluttered. It was hot. The officers took note of a white decal of an assault rifle on the front door and a decorative Samurai sword on a wall.
Todashev wore a blue T-shirt, his arms buff, his nose broken from past fights. Sometimes he sat on a mattress. The officers wore street clothes, and recorded much of the interview.
Todashev pushed back at first.
"I didn't kill nobody," he huffed.
But the officers kept pressing.
"I was involved in it," he finally said.
It was about 10:30. Todashev signed a form waiving his right to an attorney and started to jot down a confession, the report said. One of the troopers stepped outside, leaving the FBI agent and the other trooper with Todashev.
He looked nervous, the report said. He twitched. He sucked down cigarettes and went to the bathroom four times. Noticing this, the trooper removed the sword from the wall and hid it in the kitchen. At 12:03 a.m., he texted his colleagues: "Be on guard. He is in a vulnerable position to do something bad."
When the trooper looked up from his phone, he said, Todashev had flipped a white coffee table, gashing the agent's head. The agent said he screamed for Todashev to show his hands. Instead, the trooper said, Todashev ran, grabbed the red pole and charged at them with extraordinary speed.
The agent raised his black Glock 23 handgun. He fired three to four shots. Todashev fell to his knees, the trooper said, but popped back into what the trooper described as a fighting stance.
The FBI agent fired three to four more times.
"This time, Todashev fell to the ground face-first," the agent said, "and I believed the threat had been eliminated."
Special correspondent Powers reported from Orlando and Times staff writer Serrano from Washington. Times staff writer Sergei L. Loiko in Moscow contributed to this report.Copyright © 2015, Los Angeles Times