Story highlights Dead Boston bombing suspect implicated in 2011 killings, official says

Another man, Ibragim Todashev, attacks FBI agent with a knife, is killed

Todashev had admitted to a role in a 2011 triple murder in Massachusetts

Authorities told him not to take a pending flight to Chechnya

Deceased Boston Marathon bombing suspect Tamerlan Tsarnaev participated in a 2011 gruesome triple homicide outside Boston along with a Chechen killed early Wednesday during a confrontation with the FBI and Massachusetts State Police in Orlando, Florida, a federal law enforcement official told CNN.

Ibragim Todashev, who died during the interview with authorities, not only confessed to his direct role in slashing the throats of three people in Waltham, Massachusetts, but also fingered Tsarnaev in the deaths, the official said Wednesday.

Todashev was being questioned about the slayings and his acquaintance with Tsarnaev.

Todashev attacked an FBI agent, who shot him dead, a federal law enforcement official with direct knowledge of the case told CNN.

"He used some kind of weapon," the official said, and that prompted the FBI agent to shoot the suspect.

Photos: Photos: Suspects tied to Boston bombings Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Dias Kadyrbayev, left, with Boston Marathon bombing suspect Dzhokhar Tsamaev in a picture taken from the social media site VK.com. Kadyrbayev is expected to plead guilty August 21 to charges in connection with removing a backpack and computer from Tsamaev's dorm room after the April 2013 bombing, according to a defense lawyer. Hide Caption 1 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Bombing suspect Tamerlan Tsarnaev was killed during the shootout with police in Watertown, Massachusetts, on April 19, 2013. He is pictured here at the 2010 New England Golden Gloves. Hide Caption 2 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Dzhokhar Tsarnaev was captured in a Boston suburb on April 19, 2013, after a manhunt that shut down the city. In July, he pleaded not guilty to killing four people and wounding more than 200. Hide Caption 3 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – From left, Azamat Tazhayakov and Dias Kadyrbayev went with Boston bombing suspect Dzhokhar Tsarnaev to Times Square in this photo taken from the social media site VK.com. A federal grand jury charged Tazhayakov and Kadyrbayev with obstructing justice and conspiracy to obstruct justice relating to the removal of a backpack from Tsarnaev's dorm room after the bombings. Tazhayakov was convicted of conspiracy and obstruction charges in July 2014. He faces up to 25 years in prison at his sentencing in October. He has filed an appeal. Hide Caption 4 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Robel Phillipos, a U.S. citizen, was also arrested on May 1, 2013 . He was charged with lying to federal agents about the bombing, according to court papers. Hide Caption 5 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Phillipos, Tazhayakov and Kadyrbayev are accused of removing items from Tsarnaev's dorm room after the bombings on April 15, 2013. The items they took included a backpack containing fireworks that had been "opened and emptied of powder," according to the affidavit. Hide Caption 6 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – The FBI released photos and video on April 18, 2013, of two men identified as Suspect 1 and Suspect 2 in the deadly bombings at the Boston Marathon. They were later identified as Dzhokhar Tsarnaev, 19, and his brother Tamerlan Tsarnaev, 26. Hide Caption 7 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Boston Police released surveillance images of Dzhokhar Tsarnaev at a convenience store on April 19, 2013. Hide Caption 8 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – The FBI tweeted this photo on April 19, 2013, and urged Watertown residents to stay indoors as they searched for the second suspect. Hide Caption 9 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – The FBI released photos and video on April 18, 2013, of two men it called suspects in the deadly bombings and pleaded for public help in identifying them. The men were photographed walking together near the finish line. Hide Caption 10 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – A man identified as Suspect 2 appeared in this photograph by bystander David Green, who took the photo after completing the Boston Marathon. Green submitted the photo to the FBI, he told Piers Morgan in an interview. Hide Caption 11 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – The man identified as Suspect 2 appears in a tighter crop of David Green's photo. Hide Caption 12 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Authorities later identified Suspect 1 as Tamerlan Tsarnaev. Hide Caption 13 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Suspect 2 was identified as Dzhokhar Tsarnaev. Hide Caption 14 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Suspect 1 walks through the crowd. Hide Caption 15 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Suspect 1 walks through the crowd. Hide Caption 16 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Suspect 1 walks through the crowd. Hide Caption 17 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Both suspects are seen walking through the crowd. Hide Caption 18 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Suspect 2 walks through the crowd. Hide Caption 19 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Suspect 2 walks through the crowd. Hide Caption 20 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – A photo released by the FBI highlights Suspect 2. Hide Caption 21 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – A photo released by the FBI highlights Suspect 2. Hide Caption 22 of 23 Photos: Photos: Suspects tied to Boston bombings Suspects tied to Boston bombings – Suspect 2 walks through the crowd. See all photography related to the Boston bombings. Hide Caption 23 of 23

JUST WATCHED FBI shoots man tied to bombing suspects Replay More Videos ... MUST WATCH FBI shoots man tied to bombing suspects 02:04

JUST WATCHED Police: Man linked to Tsarnaev shot Replay More Videos ... MUST WATCH Police: Man linked to Tsarnaev shot 00:53

A second law enforcement official confirmed Todashev made the confession.

The unsolved triple murder received renewed interest after it was learned that Tsarnaev was sparring partners at a local gym with one of the victims.

Investigators of the crime reported at the time that the heads of the three victims were pulled back and their throats slit ear to ear with great force. Marijuana was spread over the bodies in a "symbolic gesture," and several thousand dollars in cash was found at the scene.

Todashev told investigators the men were killed during a drug ripoff because he and Tsarnaev were afraid they would be able to identify them and tell police what happened, according to a law enforcement source.

So far, no link has been found between Todashev and the Boston Marathon bombings. However, the FBI is looking into the many connections between Todashev and Tsarnaev, whose radicalization allegedly led to the Boston bombings.

A federal law enforcement official has told CNN they were initially led to Todashev because they learned he knew Tsarnaev and his younger brother, Dzhokhar. They also said cell phone records connected Tamerlan and Todashev.

Todashev was being interviewed in the kitchen of his Florida home. He grabbed a knife, which is why fatal force was used, according to a source briefed on the ongoing investigation.

"Preliminary information indicates the agent took actions to defend himself," said a federal law enforcement official with direct knowledge of the case.

"The agent sustained non-life-threatening injuries," FBI spokesman Jason Pack said.

Investigators are awaiting test results to determine whether Todashev's DNA was found at the Massachusetts triple murder scene and whether the DNA of Tamerlan Tsarnaev also was found there.

Todashev and Tsarnaev were acquainted through a mixed martial arts center near Boston, said a source briefed on the bombing investigation.

In Orlando, an FBI team is reviewing the circumstances of the shooting, a procedure that follows any FBI shooting.

Todashev had an impending flight from Orlando, via New York and Moscow, to Chechnya, when investigators sought to interview him, according to a source briefed on the ongoing investigation. He was told not to take the flight, the source said.

Details emerged Wednesday about how Todashev had Tsarnaev's phone number in his cell phone, said the source.

Both men were members of the mixed martial arts forum Sherdog.com , along with Russian-Canadian boxer-turned-jihadist William Plotnikov, the source said.

Last month, CNN reported that Plotnikov and six others died in a July 2012 firefight with Russian forces in the southwestern republic of Dagestan, while Tsarnaev was visiting the region, according to a source briefed on the investigation.

Todashev, 27, knew Dzhokhar Tsarnaev , also a suspect in the April 15 bombings, the official said. Dzhokhar Tsarnaev, injured and captured after a manhunt, is being held by authorities. His brother died in a shootout with police.

Todashev was from the Chechnya region, as were the Tsarnaev brothers, the source said.

Todashev was granted political asylum in 2008, but he came to the United States some time before that, a federal law enforcement official told CNN. Todashev had been living in the United States as a legal resident because of that asylum claim.

In the 2011 Massachusetts triple homicide, the Middlesex County district attorney's office said at the time that the victims and two unknown perpetrators appeared to know each other and that it was not a random crime. No suspects were named then.

A source said that the FBI had been investigating Todashev for about a month.

The FBI had followed Todashev for days, his friend told CNN affiliate Central Florida News 13

Todashev "wasn't like real close friends (with Tsarnaev), but he just happened to know him," Khasuen Taramov told the TV station. "But he had no idea that they were up to something like that, like bombings and everything, you know what I mean?"

He told CNN affiliate WESH that Todashev and Tsarnaev had spoken by telephone about a month before the bombings.

"It was a complete shock to him," Taramov said.

The two met a couple years ago in Boston, where Todashev had lived and where there is a small, close-knit community of Chechens, said Taramov.

Their telephone conversation before the bombings contained nothing but routine pleasantries, he said. "It was 'How are you doing; how's your family?' That's all."

Taramov said he himself was questioned by the FBI for three hours Tuesday night. Asked what he was asked, Taramov said, "Different kind of questions like 'what do you think about bombings,' 'do you know these guys,' blah blah blah, what is my views on certain stuff."

He said Todashev was not a radical. "He was just a Muslim. That was his mistake, I guess."

Taramov said his friend had told him he had a bad feeling about the direction the investigation was heading.

"He felt like there's going to be a setup ... bad setup against him. Because he told me, 'They are making up such crazy stuff, I don't know ... why they doing it. OK, I'm answering the questions, but they are still making up some, like, connections, some crazy stuff. I don't know why they are doing it.' "

Before meeting with the FBI for a 7:30 p.m. interview Tuesday, Taramov said, his friend asked him to take his parents' telephone numbers. "He just told me, 'Take the numbers, in case something happens, if I get locked up, or whatever, call them.' You know what I mean?

"We were expecting to get him locked up, but not getting him killed. I can't believe it."

Todashev was unemployed and had been living on insurance money he received after surgery for an accident. "He used to be a fighter, MMA fighter," Taramov said, in a reference to mixed martial arts.

Todashev was arrested this month on a charge of aggravated battery after getting into a fight over a parking spot with a man and his son outside an Orlando mall. The son was taken to a hospital with head injuries, a split upper lip and several teeth knocked out of place, the Orange County Sheriff's Office said in a report.

"Todashev said he was only fighting to protect his knee because he had surgery in March," the report said. He told the police that he was a former mixed martial arts fighter, it said.

Todashev, described as 5-foot-9 and 160 pounds, was released on $3,500 bond.

Asked about the incident, Taramov downplayed it. "He had a fight in the parking lot, the two guys jumped on him ... pretty much he just defended himself against two," he told WESH. "The only mistake: he did kick their ass and left."

Todashev had recently gotten his green card and had been planning to visit his parents in Chechnya and then return to the United States, but canceled the plans, Taramov said.

Now, he added, he was planning to call his friend's parents.