Russia asked FBI to investigate bomber just 6 MONTHS ago after being spotted with 'a militant' on trip to Dagestan: Was it this known terrorist who Boston killer liked on YouTube?

Russian authorities contacted FBI in November with questions about Tamerlan Tsarnaev, police source said



It came after he was seen meeting with a person involved in militant Islamic underground movement in Dagestan

FBI never responded to the concerns, the source claimed

Tsarnaev's mother said the FBI had trailed him for five years amid fears he was inspired by Russia's Bin Laden




Speculation is growing that one of the Boston bombers met a known Jihadist terrorist in 2011 - as it emerged the FBI failed to follow up on a Russian tip that he was seen with an Islamic militant six times.

On a YouTube account widely believed to belong to Tamerlan Tsarnaev, 26, there are two videos on a playlist called 'terrorists' created five months ago that since have been deleted.

Both videos appear under the name, 'Amir Abu Dujana rabbanikaly' which is also the name used by Gadzhimurad Dolgatov, a notorious Dagestani terrorist.

Investigators are pouring over the YouTube account to see if they can confirm whether Tsarnaev had any links with Dolgatov, who was killed by Russian security forces in Makhachkala in December 2012, after a fierce gun battle.

These latest revelations question the adequacy of the U.S intelligence community, who failed to spot the national security threat posed by suspect Tamerlan Tsarnaev and his younger brother Dzhokhar, despite the repeated warnings.

Two grabs of videos believed to have been deleted from Tamerlan Tsarnaev's YouTube account that are reportedly of Gadzhimurad Dolgatov - a Dagestani jihadist who died in 2012 after a vicious stand-off with Russian security services



On Sunday, a Dagistani police official source revealed to NBC News that the Russian internal security service contacted the FBI in November with some questions about Tamerlan and handed over a copy of a case file on him.

The 26-year-old Chechen, who was living in the U.S. after being granted refugee status in 2002, first caught the eye of authorities after he was spotted meeting with a person involved in the militant Islamic underground movement in Dagestan. They met at a mosque on six occasions, the source said.



The source told NBC the militant and Tsarnaev disappeared before authorities could speak with them; they added that the FBI never responded. A senior law enforcement official said that the FBI's earlier investigation did not turn up anything and they did not have the legal authority to keep tabs on him.

The question law enforcement officials will be asking themselves is, did Tamerlan meet Dolgatov when he visited Makhachkala in 2011?



However, Christopher Swift, professor of national security studies at Georgetown University told CNN that these videos and the fact they were deleted reveal nothing concrete - just yet.



'There is no evidence that these young men were seeking to make a point about Chechnya per se.'



He said he believes it is more likely that they were trying to make a point about themselves, as if to say: 'We are warriors. we have been wronged, people do not understand us and we must be heard.'



Tsarnaev was killed by police in Watertown, Massachusetts on Friday following a gun battle with authorities. Pictures of him and his brother allegedly attending the Boston marathon and planting packages had been released by the FBI on Thursday. His brother was injured and remains in hospital.

Suspect: Tamerlan Tsarnaev, left in 2010, was identified as a main suspect in the Monday bombings at the Boston Marathon after he was spotted in surveillance footage, right) at the race. He was killed in a gun battle with police in Watertown, Mass. on Friday morning



Captured: Tsarnaev's 19-year-old brother Dzhokhar, left in April, was captured by police late on Friday in Watertown, Mass. after a nearly 24 hour manhunt. He was dubbed 'Suspect Number Two' in surveillance footage, right, taken on Monday at the race



The FBI has confirmed that Russia alerted the agency in 2011 that Tsarnaev had ties to 'radical Islam' groups in his homeland. Homeland Security sources have also revealed the agency received tips in 2012 about his ties to extremists connected to a Boston mosque.



Congress is now promising a full inquiry into what intelligence had been unearthed on the suspected bombers that could have alerted authorities.

Rep. Michael McCaul, the Chairman of the House Homeland Security Committee, called it 'disturbing' that the Chechen immigrant was 'on the FBI radar' in 2011 but was deemed to not be a risk to national security.

Congressman McCaul, a Republican in the House of Representatives from the state of Texas, noted that 'the attack on the Boston Marathon is indicative of the shift in terrorists' tactics in recent years to inspire people who are living in the United States to strike.'

'While several plots of this nature have been thwarted, this is the first to succeed,' he said in a statement after Tamerlan 's brother, Dzhokhar, was apprehended late on Friday.

'In the coming weeks the Homeland Security Committee will begin to ask how this happened, and how we can prevent it from happening again,' he said, urging Americans to 'not back down in the face of terrorism.'



Questions: Rep. Michael McCaul, the Chairman of the House Homeland Security Committee, called it 'disturbing' that the Chechen immigrant was interviewed by federal officials in 2011 but after a thorough review he was deemed to not be a risk to national security

Sen. Lindsey Graham added that the FBI dropped the ball in investigating Tsarnaev in 2011.

'Once you're brought to attention by a foreign government, I think you should have a red flag put then, to be taken off later,' Graham said on CNN's State of the Union.

'The ball was dropped in one of two ways - the FBI missed a lot of things, [or] there's one potential answer [that] our laws do not allow to follow up in a sound solid way. There was a lot to be learned from this guy. He was on websites talking about killing Americans. He went overseas... he was clearly talking about radical ideas. He was visiting radical areas.'



The FBI revealed on Friday that Tamerlan Tsarnaev was the subject of an agency investigation two years ago.



The Russian government requested in 2011 that the U.S. federal agency carefully review Tamerlan 's possible connections to Chechen extremists.



'The request stated that it was based on information that he was a follower of radical Islam and a strong believer, and that he had changed drastically since 2010 as he prepared to leave the United States for travel to the country’s region to join unspecified underground groups,' agents said.



Officials said they reviewed the man's associations with suspected extremists, his travel and education history and concluded that there wasn't incriminating information to prove he had extremist leanings.



Past: The brothers grew up in Kyrgyzstan, in the town of Tokmok, home to a Chechen community in the Central Asian nation. The family left Kyrgyzstan and moved to the Republic of Dagestan, in the North Caucasus region. From there they traveled to the United States in 2002, when they were granted refugee status

'Inspiration': One theory is that Tamerlan Tsarnaev was inspired by Doku Umarov, a Chechen terrorist known as Russia's Bin Laden

'The FBI also interviewed Tamerlan Tsarnaev and family members. The FBI did not find any terrorism activity, domestic or foreign, and those results were provided to the foreign government in the summer of 2011.'

One theory into the motive for the bombings is that Tamerlan and Dzhokhar may have been ‘inspired’ by a rebel leader known as Russia’s Bin Laden.

Doku Umarov, like the Tsarnaev brothers, is an ethnic Chechen from the war-torn Caucasus region that lies between Europe and Central Asia. He has been accused of masterminding some of the worst terrorist atrocities in Russia, including suicide bombings carried out by two women on Moscow’s Metro system in 2010 which killed at least 40.

Security sources have also said that that officials at the Department of Homeland Security became interested in Tamerlan in 2012, after he spent seven months in Russia, from January to July

When traveling to Russia last year, he may have done so under an alias, according to chairman of the House Intelligence Committee, Rep. Mike Rogers.

The visit 'would lead one to believe that that’s probably where he got that final radicalization to push him to commit acts of violence and where he may have received training' in terrorist techniques, Rogers told NBC.

A DHS source suggested to MailOnline that Tamerlan was on the radar of agents in Boston after he returned to the U.S. Federal law enforcement officials reportedly received tips in 2012 expressing concern over radical, anti-American Muslims at a mosque in Boston, the source said.



Allegations: Zubeidat Tsarnaeva, left the mother of Tamerlan and Dzhokhar, told the media on Friday that the FBI had been monitoring her oldest son, Tamerlan. The boys' father Anzor Tsarnaev, right, similarly told the media that officials in the U.S. had questioned his 26-year-old son, who died on Friday after a gun fight with police



Family: The brothers, pictured as children, were very close and as the older son, right, reportedly developed extremist ideas his younger brother, center, is said to have followed his lead

Tamerlan was said to have been named as one of the radicals that came to attention of an informant working with an agency attached to the Boston-area Joint Terrorism Task Force (JTTF).



A second source, formerly assigned to a U.S. JTTF, confirmed to MailOnline that 'there is some very quiet discussion in the Boston JTTF about this'.

After the Russia trip, Tamerlan was also reportedly thrown out of his local mosque for 'crazy' behavior after getting involved a 'shouting match' with his imam according to one member of the congregation.

He was ejected from the Islamic Society of Boston Cultural Center three months ago for claiming that Martin Luther King Jr. was not a man Muslims should look to emulate. His imam had mentioned the civil rights leader during a prayer service.

'You cannot mention this guy because he’s not a Muslim!' the congregation member recalled Tamerlan shouting, shocking others in attendance.

One national security expert told the MailOnline that is might be too early to judge whether or not the FBI is to blame for dropping the ball on monitoring Tamerlan for alleged extremist ties.

Though a foreign government might express concern over an individual's ideological leanings, little can be done without proof a person violated U.S. law by providing material aid to terrorists, Professor Ron Sievert, who teaches national security law at Texas A&M, told the Mail.

Justice: Officials apprehended Dzhokhar Tsarnaev on Friday night in Watertown, Mass.

'It is hard to say before the FBI reviews the details whether or not mistakes were made in 2011. My guess, therefore, is that [ Tamerlan] was on their radar and was checked on to a degree, but that there was not enough information to warrant 24 hour surveillance, ' said Professor Sievert .



'Under U.S. law we could not arrest Tamerlan just because he was linked with Islamists by a foreign government, and we could not arrest him just because he accessed Islamist sites on the net. Under our First Amendment we could not arrest him for making pro Islamist or anti American statements. (In fact our courts have not prevented bomb making sites from being placed on the net.)'

Amidst the calls for scrutiny into what the FBI did or did not do, Sievert expressed his confidence in the leadership of FBI Director Robert Mueller.

'Bob Mueller is undoubtedly the best FBI Director I have observed in 30 years working law enforcement and national security matters. No one demands more of his agency and has been as successful in a very difficult environment,' he said.

On Friday afternoon, as the city of Boston was under a security lock down while hundreds of law enforcement officials hunted for the remaining bombing suspect, the Tsarnaev 's mother told the media that her older son had been on the FBI's radar and claimed that they were afraid of him.



In an interview with Russia Today , Zubeidat Tsarnaeva, alleged that the FBI had been monitoring Tamerlan for being a 'leader' in a religious politics movement.

'My son Tamerlan got involved in religious politics five years ago. He started following his own religious aspects,' she said. 'They used to tell me that they were controlling him, he was a serious leader and they were afraid of him.'



Evidence: Investigators gather evidence at a backyard boat on Saturday at the home where the 19-year-old Boston Marathon bombing suspect was captured

His father, Anzor Tsarnaev, similarly said that officials had been closely watching Tamerlan, claiming that FBI agents had visited the brothers in Cambridge, Massachusetts on five occasions, most recently 18 months ago.



'They said there were doing preventive work. They were afraid there might be some explosions on the streets of Boston,' the father said.

He added to the Channel 4 News that Tsarnaev had told his parents that the FBI called him in the days after the bombings to accuse him of the attacks, and he simply responded to them: 'That's your problem.'

Channel 4 News suggested that, while the claim was likely not true, it was perhaps his way of preparing his parents for the news of his involvement.



Relatives have said how Tamerlan began to develop radical religious ideas in 2009.

The suspect's uncle, Alvi Tsarnaev, told the Boston Globe his nephew, Tamerlan , visited his father in the Republic of Dagestan, which borders Chechnya.

The brothers grew up in Kyrgyzstan, a former republic of the Soviet Union, in the town of Tokmok, home to a Chechen community.

The family left Kyrgyzstan and moved to the Republic of Dagestan, in the North Caucasus region. From there they traveled to the United States in 2002, when they were granted refugee status. The two suspects lived in Cambridge, Massachusetts.

Worship: A banner reading 'United We Stand For Peace on Earth' stands outside the Islamic Society of Boston mosque in Cambridge, where the two suspects occasionally worshiped

Dzhokhar became a naturalized citizen on September 11, 2012 while his brother Tamerlan was in the U.S. on a Green Card. Their parents have since returned to Dagestan, where they still live.

Chechnya has been the scene of two wars between Russian forces and separatists since 1994, in which tens of thousands were killed in Russian bombing. It has spawned an Islamic insurgency that has carried out deadly bombings in Russia and the region, although not in the West.

Tsarnaev's younger brother, Dzhokhar, was not a subject of the 2011 FBI investigation but those who knew the 19-year-old said that he was heavily influenced by his older brother and reportedly began embracing Tamerlan's ideological leanings.

'He talked about his brother in good ways,' Pamala Rolon, an residential adviser in the dorm where Dzhokhar lived at the University of Massachusetts at Dartmouth, told the Washington Post. 'I could tell he looked up to his brother.'

Now federal officials are trying to piece together what motivated the Tsarnaev brothers to allegedly plant explosives in the crowd of the Boston Marathon, killing three in the blast and injuring more than 180.



President Obama assured the American people on Friday, after the surviving suspect was captured, that a full investigation would be launched to determine the motivation behind the deadly attacks.



While committing extensive resources to the investigation, the president also urged that caution be used before reaching conclusions about the suspects.