One brother posted messages on the Twitter social media website typical of an average American teenager; they were about his favourite television shows, food and daily habits. The other posted videos on YouTube. But they were about Islam, and an extremist Chechen singer performing ballads about jihad and a Russian militant holding a gun.
These personal online accounts apparently belonging to Dzhokhar Tsarnaev (19) and his other brother, Tamerlan (26), pull back the curtain a little on the lives they led.
But still shrouded in mystery is how the older of the two ethnic Chechens, living in the US for more than a decade, became radicalised enough allegedly to involve an impressionable brother in the Boston Marathon bombings. It is also still not clear whether international militants inspired or aided Tamerlan.
Intelligence failures
The failure of US law enforcement agencies to respond to red flags raised about Tamerlan and his leanings towards radical Islam and jihadist causes in the Muslim regions of Russia exposes the American intelligence community to charges of being responsible for one of its worst failures since the 9-11 attacks of 2001.
Specific details of the concerns about Tamerlan’s radicalisation appear not to have been shared by Russia with the US.
The picture emerging of Tamerlan is of an immigrant who became alienated by life in the US and drawn to radical Islamic beliefs. He gave up alcohol, grew a beard and became more devout, praying five times a day, as is the Muslim tradition. He disrupted sermons at his mosque and questioned what he saw as the iman’s soft views on Islam.
Tamerlan quit music school believing it was not supported in Islam and started reading jihadist websites and extremist propaganda. He also became more agitated about the US wars in Afghanistan and Iraq.
An enigmatic figure named “Misha”, an Armenian convert to Islam, has surfaced as someone who may have helped mould Tamerlan’s radical interpretation of Islam. Described as an older, heavy-set bald man with a long reddish beard, he met Tamerlan at a mosque in the Boston area around 2008 or 2009.
Tamerlan’s father is said to have been uneasy at the influence Misha had on his son, though his mother Zubeidat rubbished claims that Misha radicalised her eldest son.
Russian alarm
By the time Tamerlan travelled to Makhachkala, the capital of the Russian region of Dagestan, in January 2012, his radicalisation had already sounded alarm bells within Russia's internal security services.
The first request came in March 2011. The Russian authorities asked the FBI's office in the US embassy in Moscow for more information on Tamerlan, citing concerns about his plans to join underground groups.
The FBI’s office in Boston investigated and went as far as interviewing Tsarnaev and members of his family during a three-month investigation. By June 2011 they could find not evidence linking him to extremists. The FBI passed its findings on to the Russians in August 2011 and asked for more information from Moscow. None came.
In September 2011 the Russians contacted the CIA seeking similar information. The FBI heard about this and again asked Russia for further information in return. Again, nothing came.
Caucasus visit
Tsarnaev's departure on January 12th, 2012 for a six-month visit to Dagestan and Chechnya in the North Caucasus area of Russian alerted US customs authorities, the head of homeland security Janet Napolitano told a Senate committee. But his travels did not trip an alarm on a database known as Terrorist Identities Datamart Environment, or Tide for short, because variants of his name and birth date were logged. It is not clear whether the FBI or the CIA were notified of his travels last year.
The CIA had posted his name on the Tide database 18 months ago after Russian intelligence flagged him as a possible Muslim radical. The list is the source from which the FBI creates its terrorist screening database and the “no fly” list.
Anti-terrorism intelligence units in Massachusetts, overseen by the state police, were never notified that FBI agents had examined the activities of Tamerlan, exposing another inter-agency reporting gap.
Tamerlan’s trip to Dagestan last year, investigators believe, may hold the key to his apparent radicalisation.
Dagestan
US diplomats and FBI agents flew to Dagestan this week to interview the Tsarnaevs' parents in Makhachkala, where they have lived since returning from the US several years ago.
Both brothers spent most of their childhoods in central Asia and the search for what turned them into alleged bombers leads to their ancestral Caucasus homeland.
Dagestan is now the most dangerous republic in Russia, and the epicentre of an insurgency that in recent years has spread from Chechnya to neighbouring regions and added a strong Islamic streak to its original drive for independence from Kremlin rule.
Bomb and gun attacks on police are everyday occurrences, and rights groups say the authorities’ kidnapping, torturing and killing of opponents only serve to drive young men to join the rebels.
One of the reasons given by Tamerlan for travelling back to Russia was to replace a lost passport; officials say he applied for a new one but never collected it.
Tamerlan was not a US citizen, and it is not clear what passport he used to return to the US last summer.
Relatives have given different accounts of how Tamerlan spent his time in Dagestan. Some say he slept a lot and rarely went out, others say he trained at a gym, while his father says he made at least two trips with him to visit family in neighbouring Chechnya.
Tamerlan’s mother says he spent a lot of time online, studying websites on Islam, and learning Arabic so as to read the Koran in its original language. She insists that he never advocated jihad or any form of violence.
Salafi
Russian security services say Tamerlan prayed at the Kotrova Street mosque in Makhachkala, which is known as one of the few places in the republic and in Russia where radical Salafi preaching is openly heard. This deeply conservative strain of Islam has gained a foothold in Dagestan in recent years.
Security forces keep regular visitors to Kotrova Street under surveillance.
Some reports suggest it was after an earlier trip to Dagestan in 2011 – and visits at that time to the Kotrova mosque – that Tamerlan attracted the attention of the Russian authorities.
The FBI said that in early 2011 Russia asked for information on Tamerlan because it believed 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 [Russia] to join unspecified underground groups."
While some unnamed Russian security sources have said Tamerlan was suspected of having links with Islamic militants in the Caucasus, others have flatly denied such claims.
“Tamerlan Tsarnaev had no contact with the armed underground during his stay in Dagestan,” said the republic’s interior minister, Abdurashid Magomedov.
Dzhokhar had not visited the Caucasus since leaving in 2002, he said, and dismissed suggestions that Tamerlan had been “infected by radical Islam” in the region as “an attempt to shift the blame”.
'Roots of evil'
Ramzan Kadyrov, Chechnya's leader, said it was "in vain" to link his region to the Boston bombings. "They grew up in the US, their views and beliefs were formed there. The roots of evil must be searched for in America," he said.
A group believed to be linked to Caucasus rebel leader Doku Umarov also dismissed any connection between its forces and the Tsarnaevs. “The Caucasian Mujahadeen are not fighting with the United States of America. We are at war with Russia, which is not only responsible for the occupation of the Caucasus, but also for heinous crimes against Muslims,” the group said.
Russian relatives and friends of the Tsarnaev brothers seem united in believing they are being framed. Most see the Kremlin at work, and suspect it is seeking international carte blanche to continue its bloody crackdown in the Caucasus.
US officials have blamed the Russians for not providing more hard evidence or leads and for not responding to requests for more details. On their own efforts, they said they went as far as they legally could to investigate Tamerlan.
Dzhokhar, the surviving suspect, has allegedly told investigators that they were self-radicalised and self-trained bombers, unaffiliated to any group and acting alone.
