In May 2013 a FBI agent from Boston shot and killed a man in his home in Orlando, Fla., during an interrogation. The man’s name was Ibragim Todashev and the FBI was investigating his links to alleged Boston Marathon bomber Tamerlan Tsarnaev.

Nearly eight months later, the circumstances of the shooting are still a mystery.

Ibragim Todashev, in a May 4, 2013, booking photo provided by police in Orlando, Fla. (AP)

On the day of the shooting the FBI made a terse statement that Todashev initiated a "violent confrontation." But the FBI has not yet issued a report on whether the use of deadly force was justified. And though FBI Director James Comey told reporters on Jan. 9 that he was “eager” to see the report released, the bureau has shown no sense of urgency to release any details of what happened, despite widely conflicting news accounts of the shooting, based on anonymous federal sources, and accusations by Todashev’s family that he was murdered. Citing its ongoing investigation, the FBI even ordered the Florida state medical examiner to seal the autopsy report, which was ready for release in July.

What made Todashev’s shooting national news in May was what he reportedly told interrogators before he was shot. In a court filing in Boston in October, federal prosecutors stated that Todashev had implicated Tsarnaev in previous crimes — specifically the gruesome, unsolved murders of three men in Waltham nearly two years before the marathon bombing. If what Todashev was saying was true, that made him a witness to the slayings — apparently the only witness.

The revelation that Tsarnaev was allegedly engaged in gruesome crimes well before the marathon bombing intensified questions about Tsarnaev’s past and his escape from detection.

In short order of revealing what the government says he revealed during that interrogation last May, Todashev was shot dead by his interrogator; the FBI said he had attacked its agent.

An investigation of what happened in the run-up to the shooting of Todashev on May 22 provides new details and raises new questions about the interrogation that turned deadly.

A Complicated Life In Florida

“He had a bad feeling,” Khusein Taramov, a friend of Todashev's, told a reporter from Orlando's WESH-TV outside Todashev's cordoned-off apartment the night Todashev was shot and killed by the FBI agent. “They started following him and a few days ago they start following us again.”

One blip that had apparently put Todashev on the radar of the Joint Terrorism Task Force in Boston was a call he got from Tsarnaev in March, a month before the marathon bombing.

“They were never close friends,” Reni Manukyan, Todashev's wife and widow, claimed about the relationship between Tsarnaev and Todashev. “They attended the same gym.”

The 24-year-old widow, an Armenian who converted to Islam after meeting Todashev, now lives in Volgograd, Russia, after bringing Todashev's body home to Chechnya last June.

Todashev and his wife, Reni Manukyan, in an undated photo (Courtesy of Reni Manukyan)

Like Tsarnaev — the older of two brothers alleged to have carried out the bombing — Todashev was an ultimate fighter. He had moved from Boston to Atlanta in 2010, then to Florida in late 2011. His neighbors in Orlando say they used to see him practicing martial arts at the swimming pool in the middle of the condo complex. He was 5-foot-9 and weighed 153 pounds. His next-door neighbor, who was at work the night his wife heard the FBI gunshots next door, figured he must be a professional athlete and guessed soccer player.

At 27 years of age, Todashev wanted to be a professional fighter — and had a broken nose, a cauliflower ear and an explosive temper to prove it. He had been charged with aggravated battery on May 4, 2013, after he bloodied a father and son and knocked the father unconscious in a fight over a parking space.

“The only mistake he did was kick their ass and left,” Taramov told the Orlando TV reporter.

Fellow Chechens were Todashev's only friends. After Todashev had knee surgery in March, his widow says he got a call from Tsarnaev, his former gym partner in Boston.

Within a day of the wild police shootout in Watertown on April 19 that left Tamerlan Tsarnaev dead and his younger brother Dzhokhar seriously wounded but hiding in a nearby boat, Todashev ended up on the ground of his backyard in Orlando, surrounded by men with guns, say witnesses. FBI agents were looking for the Tsarnaevs’ possible co-conspirators.

They confiscated Todashev’s phones and computers, according to Manukyan and Todashev's friends. Seeing that Todashev had erased the message from Tsarnaev, investigators got suspicious. But the government filed no charges and the FBI returned his electronics the next day. Meetings and phone calls with agents became a routine for the rest of his life, which was not long.

His widow Manukyan says the FBI called Todashev into its FBI office in downtown Orlando for several interviews during the next month. He voluntarily went in. And between the interviews, “they were following him everywhere he goes,” she said.

Todashev was living a complicated life: under surveillance, in recovery from surgery, without a job; he never had a job in Florida, his wife says. They were separated and she had moved out of their rented condo and gone to Atlanta. But he was driving her Mercedes and she was sharing her checkbook with him while she was working two jobs, as a chambermaid and hotel desk clerk. Meanwhile, he was living in the Orlando condo with his new girlfriend from Moldova, Tatiana Gruzdeva, whose visa had expired.

Add to Todashev's list of complications the fact that the FBI was pressuring Gruzdeva to inform on him, she later told Boston Magazine. When she refused, she claimed the bureau reported her to Immigration and Customs Enforcement. On May 16 they locked her up.

Then came the 21st of May.

A Long Interrogation In The Todashev Condo

Todashev got a call from the local Orlando FBI agent he had been dealing with, Manukyan says. “He told him, 'Hey, there is a Boston agent who wants to talk to you and this is going to be our last conversation. We'll clear your name up. And they just want to see you.' "

At 7:30 p.m. that night, FBI agents began interviewing Manukyan in Atlanta and, simultaneously, her mother in Savannah, Ga., and Todashev in Orlando, according to Manukyan and Taramov, who was there with Todashev when the FBI arrived at the condo.

Todashev wanted his friend to be a witness; Taramov said Todashev was worried something was going to happen to him. But the FBI agent quickly separated the men, Taramov says.

Khusein Taramov is interviewed by Orlando reporters outside of Todashev's condo after Todashev was killed. (WESH-TV screenshot)

The FBI's interviews of Todashev’s wife and mother-in-law — who were never asked any questions about the Waltham murders, according to Manukyan — were short. Todashev's wasn't.

Taramov says he was interviewed by an FBI agent outside Todashev’s condo unit for three hours while Todashev was interviewed inside by a team of three investigators.

It was around 11:30 at night, according to Taramov's calculations, when the FBI agent sent him home, telling him to come back in an hour or so if he wanted to see his friend, he says.

Inside the condominium unit, I have learned from law enforcement sources, Todashev faced an agent assigned to the Boston office of the FBI and two Massachusetts State Police troopers — one of them assigned to the Middlesex district attorney. Middlesex County has responsibility for investigating the unsolved triple murder in Waltham in 2011. With the troopers' arrival, it appears the focus of interest was changing from terrorism to murder.

In the course of our investigation, WBUR has learned the names of the law enforcement officers involved in the shooting. We are not releasing the names at the request of both the FBI and the Massachusetts State Police, which cited specific concerns for their safety.

“We have received credible threat reporting against anyone that was involved in this," Kieran Ramsey, the assistant special agent in charge of the Boston FBI, said. “That has caused us to take specific actions not only to protect their identities at this time but quite literally protect them and their families.”

In Orlando, the interrogation of Todashev was extraordinarily long.

“The fact that there were multiple officers present there questioning him for a period of hours clearly indicated that Mr. Todashev did not feel that he was free to leave,” said Thomas Nolan, who chairs the criminal justice department at the State University of New York at Plattsburgh. Nolan was also a Boston police officer for 27 years.

"Mr. Todashev was obviously not free to leave if he chose so," Nolan added. "So he was in effect in custody here."

Whenever a subject is considered in custody, whenever an interview turns into interrogation, or the subject’s answers tend to incriminate him, Miranda rights become an issue. If the government wants to be able to use the subject’s statements against him, law enforcement agents must advise him of those rights, including the right to remain silent and to have a lawyer present.

Todashev had told the FBI he did not want to go into their office for another interview, but, if law enforcement agents found probable cause to arrest him for a crime, they could have handcuffed him and taken him away.

“That’s the professional standard,” Nolan said. “The practice is to remove the individual from a place that he feels familiar [with] to give law enforcement the upper hand in conducting the investigation. And that's usually a police facility.”

Whether the FBI read Todashev his Miranda rights might hinge on a balancing of objectives.

Were they more interested in getting information about possible conspirators that they might put to use on the Joint Terrorism Task Force? Or were they more interested in making sure that the information they got from Todashev regarding the Waltham murder — over which the Middlesex district attorney there had jurisdiction — could be used against him if he were to be charged with a crime and prosecuted by the state of Massachusetts? Middlesex had those murders to solve. The FBI, whose main focus is terrorism, had demonstrated early on, from the night of the apprehension of Dzhokhar Tsarnaev, when U.S. Attorney Carmen Ortiz had invoked the public safety exception, a more elastic interpretation of Miranda rights.

Did they advise Todashev of his Miranda rights? The FBI will only say it cannot comment because there is an ongoing investigation. We only know that there was no attorney present to represent Todashev.

One way the investigators could continue with their questioning was on the grounds this was not a custodial interrogation. He had invited them into his home, after all; they could try to make that argument later on. Making an argument he was not in custody would allow them to keep pushing him for answers in a place he might be more likely to keep talking than if they brought him to the FBI office where he didn't want to go. The FBI office or a police facility would also subject both the interrogation and the interrogators to protocols and controls that might not be in play at Todashev’s condo.

Getting Todashev into a police facility also had its advantages, however.

“If you're beginning to accuse somebody of a triple murder back in Massachusetts, that’s going to generate stress and crisis and conflict,” said Tom Shamshak, a police trainer, instructor in investigations at Boston University and former Massachusetts police chief.

There was a challenge and a danger in being in Todashev’s home, because it was his home — where he was most comfortable, and where, if there were any weapons, he knew where they were and the police did not. The one place police would know there were weapons was the one place they are told in training to avoid when making accusations and where they dread going when responding to calls of domestic disputes: the kitchen, which has knives.

“Once the tone changed, the setting should be in a secure environment where there are no weapons,” Shamshak said.

And remember, if Todashev was a material witness to those triple murders in Waltham, the police have a responsibility to keep him safe and secure as witness or suspect.

Maybe the FBI agent and the state troopers felt safety in numbers. But in front of them they had someone they knew to be skilled at ultimate fighting, who possessed a hair-trigger temper, and was trailed by a reputation for violence.

“Could this have been avoided?” Shamshak asked rhetorically. “Yeah, it probably could have been avoided had Todashev's interrogation been taken into a local police station, state police office [or the] FBI office.”

But how do you get him there if he hasn’t been arrested?

“Well, they’re the FBI,” Shamshak replied to my question. “They’re quite capable of encouraging somebody or coercing somebody to come along,” he chuckled.

“And there were opportunities here: ‘Oh, you’re a material witness and we have probable cause to arrest you for obstruction of justice.' Something as simple as that.”

They also could have invited him to go. It’s been known to have worked.

'I Was There, But I Didn’t Do The Murders'

The living room in Todashev's Orlando condo where the interrogation took place, as seen through a window (David Boeri/WBUR)

Todashev’s condominium unit sits within a mile of Universal Studios in Orlando, on Peregrine Avenue, where white ibises were wading at the pond out back when I visited in December. Peering through a low window, I saw a table and a folding chair in the otherwise-empty unit. It was the only chair that was ever there, Manukyan recalls.

I was with Hassan Shibly, an attorney and executive director of the Florida chapter of the civil rights group known as the Council on American Islamic Relations.

“If you have one chair — which we can assume Todashev sat in, surrounded for five hours by several armed officers, without an attorney present — it raises a lot of questions,” he said.

Months earlier there, Todashev was questioned about the murder of three men butchered in Waltham, according to sources. One of those victims was Brendan Mess, a mixed martial arts fighter, just like Todashev and Tamerlan Tsarnaev. The three of them trained at the same gym when Todashev lived in Boston. Tsarnaev called Mess his best friend.

On the 10th anniversary of the Sept. 11, 2001, terrorist attacks, at least one assailant went to Mess’ apartment and slit his throat. The assailant or assailants did the same to two other men in the house and then littered marijuana and $5,000 cash over all three bodies.

Manukyan says her husband was never questioned before about the Waltham murders and he never talked about Mess. But those questions were coming now.

“The accusatory tone in an interrogation ... it's hot,” Shamshak said. “So you have a hot, volatile back-and-forth with the officers: ‘I don't want to hear that. I know you did it.’ It’s like a volcano.”

And, at some point in the long night of a very long interrogation, Todashev broke, according to law enforcement sources familiar with accounts of what happened who requested anonymity because they do not have permission to speak publicly.

“I was there, but I didn’t do the murders,” Todashev said, according to those sources. Under the heat, they say, Todashev blamed Tsarnaev for the murders.

They were coming up to midnight, in their fifth hour, and they were sweating; it was unbearably hot, one of the officers there would later recount, according to sources. Had they all been in a police station or an FBI office, they would have been cooler and safer. But they felt a sense of urgency, law enforcement sources told me.

They knew Todashev was planning on going home to Chechnya. (He had tickets to leave the country in two days, Manukyan said, and after he was shot to death, investigators found presents for his family upstairs, as well as $4,000 in his pocket, according to the search warrant returned to the court by the FBI.) As late as it was, the three officers were close to finishing up. They were almost done. What remained, according to sources, was to get Todashev to write his admission or confession.

Sources say the state trooper who was assigned to the Middlesex district attorney left the living room to make a call to higher-ups back in Middlesex — no ordinary call at midnight. Normally, according to the protocols of the DA’s office, a prosecutor would be present for a custodial interrogation of such importance, standing outside “the box” and available to answer questions or provide counsel to the interrogators. But that did not happen in Orlando.

With that state trooper out of the room there were only two officers with Todashev: the FBI agent and the other state trooper. At no time during their interrogation or after he supposedly admitted to being present at the Waltham murders was Todashev handcuffed, sources say.

“A reasonable and prudent investigator before conducting an accusatory interrogation would ensure his or her safety and the safety of his subject in question,” Shamshak said.

At one point while Todashev was out of the small living room, the state trooper who was still in the room saw what he considered a potential weapon that had been lying within reach of Todashev, and he hid it, according to law enforcement sources. It suggests that at least one of the officers seemed aware of the danger.

In conflicting news accounts that followed the shooting, Todashev was described as wielding all sorts of unusual weapons in “the violent confrontation” the FBI claimed he “initiated." Afterward, according to the search warrant and multiple sources, the FBI’s evidence response team collected 76 items from Todashev’s unit.

“We had a yellow broom, a metal broom and then there was a mop. So they took the mop,” Manukyan said. What is referred to as a “broomstick” in the search warrant return, she says, must be the mop she found missing when she finally gained access to the condo after the FBI evidence team left. Investigators also collected a number of kitchen knives and blades, she says, as well as a ceremonial sword that she remembered as dull and broken long before that night.

“The handle was broken," she said. "That thing was trash to me.”

If the broomstick and ceremonial sword were being considered weapons, Manukyan asked, why didn’t the investigators act like they were dangerous on the night of the interrogation?

“They were with him almost five hours before they kill him," she said. "I’m sure they would have put these things somewhere far away from him if they were afraid he would grab something.”

A Short-Lived Burst Of Chaos

The weapon Todashev did not have was a gun.

It was close to 12:15 in the morning, according to law enforcement sources. Todashev returned to his chair and writing table. He had to make a formal written admission of what had happened to Mess and two other men in Waltham. Taking note of Todashev's agitation, the state trooper texted the FBI agent beside him to warn him that the subject sitting in front of them might go off, those law enforcement sources say.

As Todashev began a statement he never wrote out, my sources continue, he did go off. He suddenly pushed the table into the FBI agent, knocking him over. The trooper would say he never saw a human being move so fast as Todashev, those sources say. In the short-lived burst of chaos, according to this account, the trooper saw Todashev coming at him with “a pipe” and believed Todashev would have split his skull if the agent had not shot first.

The FBI would say the agent’s injuries did not threaten his life; they required stitches to his head. But the seven shells collected after the shooting suggest the agent fired seven shots at Todashev. The trooper did not fire his weapon, he later said, because he was afraid he might shoot the agent in any crossfire, according to my sources.

Sources say the FBI agent fired in two bursts. With a burst of three bullets, Todashev went down, according to this account. Then, to the amazement of the agent and the trooper, the ultimate fighter Todashev came up again. The agent fired four more. It was 12:15, the official time of death, Manukyan says.

Abdul-Baki Todashev holds a photo he claims is of his dead son, Ibragim, during a news conference in Moscow, Russia, on May 30, 2013. The father, who says agents killed his son “execution style,” showed journalists 16 photographs of Ibragim in the morgue with what he said were six gunshot wounds to his torso and one to the back of the head. (Alexander Zemlianichenko/AP)

“It’s not good for anyone when a suspect ends up dead,” Shibly, the civil rights attorney, said outside the condominium unit in December. “That effectively kills off the trail and it leaves a lot of questions unanswered.”

Within a few hours, a FBI agent and two Massachusetts state troopers had solved a murder case that had been unsolved for nearly two years (or so federal prosecutors would later signal) and then having solved it, they shot and killed their eyewitness, after having gotten into circumstances that had jeopardized their lives as well as his.

It was in self-defense, they said, according to sources. And a shooting incident review would determine if the agent was justified in using deadly force, the FBI promptly announced. The Florida state attorney later announced that he would conduct a review as well.

Shibly, whose Council on American Islamic Relations also represents Todashev's father, says the focus of the shooting incident review may be too narrow.

“It appears the investigation is only looking at the actual second the officer pulled the trigger as to whether he was scared for his life,” he said. “It’s perfectly plausible to see a situation where the FBI agent created a situation where he put himself and Todashev in danger, either through his own negligence or through violating Todashev’s civil rights, and yet still be justified in killing him, even though he wrongfully created this dangerous situation.”

Hassan’s statement suggests the basis for the wrongful death suit Todashev’s father is planning to file.

At the end of May, a search warrant return cataloguing what had been collected by the FBI’s Evidence Response Team showed that they took the small writing desk that was presumably used in Todashev’s alleged attack on the agent. In late December the folding chair Todashev sat in while at the table was still in the vacant condo unit. What’s still missing in January is the long-awaited report from the FBI.

“I don’t think that will ever be solved,” the widow Manukyan said from Volgograd, which suffered its own tragedy from terror bombings while we were corresponding for this story.

She added: “I don’t think we ever will know the true [truth] of what happened in [Orlando].”

Todashev's family points to post-mortem photos and claims he was murdered, shot in the top of the head.

Eight months later the autopsy performed by the Florida state medical examiner’s office that might put those claims to rest remains under seal at the orders of the FBI. The FBI says it cannot comment while the investigation is active. It has not yet released its report on whether the shooting was justified.

Correction: An earlier version of this piece misspelled Hassan Shibly's last name. We regret the error.

Editor's note: Some comments in the thread below have been removed for violating WBUR’s community discussion rules.

1/15 Update: Here's Part 2 of the WBUR investigation.