On May 15, we reported a possible link between deceased Boston Bombing suspect Tamerlan Tsarnaev and the gruesome murder of three Jewish pot dealers in Waltham, MA on September 11, 2011. On May 22, that link was apparently confirmed when 27-year-old Ibragim Todashev, an associate of Tamerlan’s, allegedly confessed that the two of them had committed the crime during an FBI interview in his home, during which he was shot and killed.

Todashev was a fellow Chechen martial arts enthusiast who had trained with Tsarnaev in Watertown, MA before moving to Orlando, FL several months ago. It was Tsarnaev’s cell phone records that led the FBI to Todashev. According to his best friend Khusen Taramov, Todashev had been called almost daily by agents since the bombings, granting numerous interviews to the FBI over the past few weeks. Investigators told NBC News that Todashev had been cooperative – even postponing a flight back to Chechnya in order to do yet another interview, which he had reportedly been assured would be the last one, after which he would be cleared.

“They told us they needed just one more interview,” Taramov said. “They said the case was closed after this.”

As it turned out, it would indeed be his last interview – but instead of ending in his exoneration, it ended with his execution.

The interview was conducted by an FBI agent, two state troopers, and several other law enforcement personnel in Todashev’s kitchen on the night of May 21. Authorities had reportedly determined that there was no indication that he’d been involved in the bombing; but surprisingly, when the Waltham murders apparently came up, Todashev allegedly implicated both Tamerlan and himself as the perpetrators. Then, in the midst of writing out the confession, they claim Todashev suddenly “just went crazy,” flipping over the table and lunging at the FBI agent.

“They got him to confess to the homicides, and they say, ‘Let’s write it down,’ and he starts writing it down,” a senior official told the NY Times. “He goes to get a cigarette or something and then he goes off the deep end. I don’t know what triggered him, and he goes after the agent.”

It was at this time that officers opened fire, shooting him seven times – including once in the back of the head – and killing him. Why such lethal force was necessary remains unclear, as the official story continues to change. Initial reports stated that Todashev had attacked the agent with “a knife or a pipe or something,” but two of the three unnamed sources who reported the knife later backtracked, saying they weren’t sure exactly what had happened. Later, several unconfirmed reports indicated that Todashev had a sword, a metal pole or a broomstick. Then on May 29, The Huffington Post reported that an unnamed FBI source confirmed that Todashev was in fact unarmed when he was shot.

These inconsistencies beg the questions: why couldn’t a cadre of skilled law officers determine whether or not the suspect had a weapon or identify what it was, and – with information crucial to an important case – why couldn’t they subdue him without killing him?

On Thursday, May 30, Todashev’s family held a press conference in Moscow, during which his father, Abdul-Baki Todashev, accused the FBI of executing his son.

“Maybe my son knew something, some information the police did not want to be made public,” he speculated. “Maybe they wanted to silence my son.”

He also produced photographs of his son’s body showing the bullet wounds, apparently taken by Taramov at the morgue when he went to identify the body. Taramov claims that on the night of the shooting, the FBI interrogation had lasted for eight hours, and just prior to the interview Todashev told him he was worried that he was being setup.

“He told me, ‘They are making up such crazy stuff,’” he told CNN affiliate WESH. “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.’”

Taramov and Todashev’s estranged wife Reni Manukyan had also been interviewed several times by FBI agents in recent weeks and said that at no time had any of them been asked about the Waltham murders – only about Tamerlan Tsarnaev and the bombing.

“It never, ever came up,” Manukyan told the Boston Globe. “Everything they asked was about the bombing.”

The agent alleges that Todashev told them the murders were the result of a botched drug rip-off, and that the victims were killed so that they couldn’t identify the assailants. But this motive seems inconsistent with the evidence. If it was a drug rip-off, why leave the $5,000 cash and seven pounds of marijuana behind? And why “behead” the victims on the 10th anniversary of 9/11 and cover their bodies with marijuana? These factors seem to indicate a far more personal, perhaps even fanatical, motive.

It’s already been established that Tsarnaev had become radicalized – giving up alcohol and marijuana and expressing his desire to engage in jihad and “willingness to die for Islam.” Considering that the victims were all Jews with ties to Israel, and were possibly selling marijuana to his little brother Dzhokhar, it’s seems more likely that this was a hate crime than a robbery gone awry. What’s unclear, however, is why Todashev would have become involved when his family and friends all insist that he was not a radical and would not be involved in anything related to drugs.

"My husband – he does not do drugs, he does not smoke, he doesn't do anything like that," Todashev's wife Reni Manukyan told the Wall Street Journal. "He doesn't even drink alcohol."

Aside from having no apparent motive, Todashev may also have had an alibi. At the press conference, Ms. Manukyan claimed that she has records proving her late husband was with her in Atlanta on September 11, 2011, and therefore could not have committed the killing in Waltham.

The FBI has not released any official findings and still has not gone on record regarding the case, other than to say that a review team from Washington is supposedly investigating the circumstances surrounding the shooting. On Wednesday, May 29, the Council on American-Islamic Relations called for a separate probe by the U.S. Department of Justice to determine whether or not Todashev’s civil rights had been violated and whether the use of lethal force was indeed justified.

With the results of DNA tests from the crime scene supposedly pending, Middlesex District Attorney Marian Ryan issued a statement declaring that the Waltham murder investigation “is by no means closed.” In the meantime, the alleged confession and death of Ibragim Todashev reeks of suspicion, and raises more questions than answers. Were the murders the result of a robbery gone awry or a hate crime? If the former, why did the killers leave the marijuana and cash behind? If the latter, why did Todashev become involved – and was Dzhokhar involved as well? Also, after being so cooperative through many hours of interviews – even to the point of confessing to three murders – why would Todashev suddenly decide to attack a federal agent? Why couldn’t a cadre of skilled law officers subdue him without killing him? And perhaps most importantly, if the police had done a better job of investigating the Waltham murders to begin with, could the Boston Marathon bombing have been prevented?