Until the terrible events unfolded in Boston this week, for the Russell family of Rhode Island, the 26-year-old suspected Boston bomber was not a terrorist but the man who married their young daughter Katherine, then 21, converted her to Islam and fathered her a child.
Like all of America, the family struggled on Saturday to make sense of how – as Barack Obama put it when he addressed the nation – two young men who grew up and studied in America, "as part of our communities and our country", could resort to such violence?
The Russell family had no answers: "We cannot begin to comprehend how this horrible tragedy occurred," the family said in a statement, delivered through a half-opened front door, "In the aftermath of the Patriot's Day horror, we know that we never really knew Tamerlane Tsarnaev." Perhaps his wife or younger brother Dzhokhar, 19, who was still in a serious condition in hospital yesterday – will provide some of the answers.
Getting to know Tamerlan – as the FBI spelled his name – and Dzhokhar and unraveling their journey from grateful, wide-eyed immigrants to the point where they were able and willing to murder and maim, is now the urgent task of investigators, and the US nation as a whole.
The barest facts are these. The brothers grew up in the Chechen community in Kyrgyzstan, and then the family moved to the Russian region of Dagestan around 2001, where they studied at the capital Makhachkala's respected School Number One.
By 2003, when Tamerlan was in his early teens, and Dzhokhar was just eight, the boys moved to the United States as refugees, settling in Massachusetts where their father worked as a car mechanic, training his two athletic young sons in boxing and martial arts. Ten years later, they would become the Boston bombers.
Piece by piece the information is emerging, each new scrap of testimony arriving like competing brush-stokes on a canvas that will take many months of painstaking work for the police and the FBI to build up - layer upon contradictory layer - until something as close as possible to the truth emerges.
In 2004, after winning a 'Golden Gloves' amateur boxing competition in nearby Lowell, Massachusetts Tamerlan, then 14, was apparently full of praise for his new home. "I like the USA. ... America has a lot of jobs.
That's something Russia doesn't have," he told his local newspaper, "You have a chance to make money here if you are willing to work." John Allan, owner of Wai Kru Mixed Martial Arts Boston where Tamerlan used to train remembers – at least, back in those early days – a respectful, disciplined young lad, and a brilliant fighter.
"He was the best boxer in Boston, He smoked all the professionals," Mr Allan told the Boston Globe, adding that boy's father, Anzor, had done a good job with his son. "They were an incredible family," he added, "This was so shocking to me." Both boys went to high school at Cambridge Rindge and Latin, a state school in Massachusetts known for being ethnically and socially diverse and for having the actors Matt Damon and Ben Affleck, and the poet E.E. Cummings among its alumni.
It was a far cry from sparse, but well-scrubbed School No.1 in Makhachkala where the boys studied from the end of September 2001 to March 2002. The Sunday Telegraph visited it yesterday, seeing children seated at low green desks, reading and – in one - singing a song to their teacher.
Asked by the director Magomed Davudov what things they should never do, a six-year-old girl replied: "You should never kill someone, and you should look after nature."
It is in recollections from their American High school that the temperamental differences between the two brothers begins to emerge.
Tamerlan concentrated hard on his boxing, aspiring to compete in the Olympics and to fight for the US rather than Russia. There were, though, clear indications that he was failing to fit in to American life.
Between autumn 2006 to 2008, Tamerlan enrolled for three semesters on part-time accounting course at Bunker Hill Community College in Boston but, again he didn't seem to fit in. "He wasn't even close" to getting a degree, according to a spokeswoman for the college.
"I don't have a single American friend. I don't understand them," Tamerlan told an interviewer in 2009 before another boxing competition, lamenting the breakdown of "values," in America and voicing worries about the general excess of American life, observing "people can't control themselves."
Pictures from that time show a young man in love with himself, if not the world around him. On the way to the gym, he poses in front of his Mercedes car in brilliant-white moccasins, black trousers, carrying the accessories – from sunglasses to smart phone – that American kids dream of.
But in all the avalanche of recollections and testimony that have poured fourth this week, there appears to be – as Tamerlan himself said – not a single American friend prepared to testify to something good in the suspected bomber.
The contrast with Dzhokhar could not be more plainer. Perhaps because he had arrived in the US at a younger age, he showed no such signs of having difficulty settling down, being remembered by a plethora of school and university friends as a gregarious, fun-loving character who spoke accentless English, enjoyed socialising and was an admired leader on the school wrestling team.
He was one of 45 high-school seniors to receive a $2,500 scholarship from the city of Cambridge, and former classmates remember a popular, all-American boy who was one of the crowd, wearing a black tuxedo and red-bow tie to his senior prom.
"He was happy to be there, and people were happy he was there," Sierra Schwartz, now 20, told the New York Times. "He was accepted and very well liked."
"Everything about him was wonderful," added Larry Aaronson, a retired history teacher at Cambridge Rindge and Latin School. "He was completely outgoing, very engaged, he loved the school. He was grateful not to be in Chechnya."
Outwardly, that sunny disposition seems to have continued in Dzhokhar right up until the end, with dorm-mates at the University of Massachusetts, Dartmouth recalling that as late as last Wednesday night – when he attended a soccer team party – he was same easy-going college kid.
Unlike his older brother, Dzhokhar also had the occasional cigarette and a girlfriend off-campus who is believed to be among three people to have been questioned by police.
"He was nice. He was cool. I'm just in shock," said 19-year-old Florida Addy, who lived in his dorm.
"To be quite honest, he was one of the nicest kids I know," Zachary Boyer who lived two doors down from Dzhokhar told USA Today, "very socially out-going, he went to parties, I saw him out plenty of times, we hung out with him on multiple occasions and I can't even believe what happened."
However, at some point around 2009 the edges of the picture start to darken, particularly for Tamerlan.
His aunt Maret Tsarnaeva, who lives in Toronto, said she noticed a change, particularly in Tamerlan's attitude to religion. "He was not devout, practicing. But about three years ago he began praying five times a day," she said, adding that she didn't disapprove.
At around this time, Tamerlan met Katherine Russell, a 21-year-old freshman student at Suffolk University in Boston who became his girlfriend, and later wife, and would often be seen out walking in the Rhode Island neighbourhood with Tamerlan and their baby on weekends, according to neighbours.
Neighbours said that Mrs Tsarnaev – she took her husband's name – had converted to Islam and would dress in loose-fitting clothing and wear a veil over her hair, in keeping with Islamic traditions. Despite the unusual set-up in such a neat, conservative town, one neighbour Paula Gillette, 51, told The Sunday Telegraph of the delight of Mrs Tsarnaev's father, Warren who is a doctor, and her mother, Judith, a nurse, at the arrival of their grand-daughter Zahara, now three. "They were so happy to have a grand-daughter," she said, "This is terrible for them".
But behind the veil, there were reportedly problems that perhaps spoke to the rage growing within Tamerlan, with the website spotcrime.com reporting that he had been arrested for domestic violence in July 2009 after assaulting a woman.
His cousin, Zaur Tsarnaev, 26 made similar allegations about Tamerlan, drawing the contrast with his "sweet innocent" brother Dzhokhar.
"He was always getting into trouble. He was never happy, never cheering, never smiling. He used to strike his girlfriend," Zaur told the Boston Globe from the Dagestani capital, adding "I used to warn Dzhokhar that Tamerlan was up to no good." As recently as 2011, there were still apparently no outward signs – even to trained eyes - that the two brothers were moving towards adopting what now appears to be some form of violent jihadist beliefs.
That year, the FBI admits it interviewed Tamerlan "at the request of a foreign government" - understood to be the Russians - but reportedly found no "derogatory" information on the young man, and therefore, as one official put it, the matter was "put to bed".
Dzhokhar also gave nothing away, at that time working a job as a lifeguard at Harvard university where coincidentally the man who hired him, George McMasters, was an ex-marine who says he interrogated prisoners in Guantanamo Bay for the National Guard in 2003 and 2004.
"It is surreal for me, considering that I have been dealing with these guys for 10 years," Mr McMasters, 56, said, recalling the quiet and respectful young man he hired, "And then I come home, and they are in my backyard, in my pool."
One of his fellow life-guards, Rose Shutzberg, an fellow high-school senior who admitted having a crush on Johar – as he was known to his friends – said she was still completely baffled by what had happened.
"I even had a crush on him. Whenever I was speaking to him I felt safe," she told NBC News, "it's something I'm still struggling with. I don't really understand how [to reconcile] the Johar I knew and the Johar being portrayed throughout the media." But latterly, there were some signs – not that the two brothers were preparing to commit the atrocity that transpired at the Boston marathon last Monday – but other indications that, with hindsight, something fundamental had changed.
After a seven-month stay in Russia last year – a 'lost' period that investigators will now be scutinising minutely – the YouTube channel bearing Tamerlan's name began to feature jihadist materials.
There was a rant by the Australian jihadist cleric (and ex-boxer) Feiz Muhammad and another featuring the Millenarian prophecy, often cited by al-Qaeda linked groups of the Black Banners of Khurasan, that dreams of the time when an Islamic force will purify Central Asia.
Whatever triggered Tamerlan's radicalisation, family friends in the Dagestan capital yesterday said it was not his parents, Anzor and Zubeidat, who seem to have had as much difficulty processing their two son's transformation as many of their friends.
"The family had nothing to do with the Wahhabis," said Vyacheslav Kazakevich, 36, a neighbour, referring to the conservative Muslims who are linked to the Islamist insurgency that operates from the vast forests outside the Makhachkala, "Anzor is a hard worker who does favours for people. He owns a perfume shop and he wanted to open another one here."
But by September 1 last year – just 10 days before Dzhokhar became a US citizen – there were signs that the once happy-go-lucky younger brother had too become infected with his brother's anti-American feelings.
'Idk [I don't know] why it's hard for many of you to accept that 9/11 was an inside job, I mean I guess f--k the facts y'all are some real £patriots £gethip," he wrote on his Facebook page.
Later he would taunt America over al-Qaeda's most successful terror attack, "September 10th baby, you know what tomorrow is. Party at my house! £thingsyoudontyellwhenenteringaroom.
And then only a week ago, Mr Allan, the owner of the martial arts centre where Tamerlan trained, received an email saying after two years away, the once-respectful boy had come back to the gym, but now he acting rude, and walking on the mats with his shoes.
Perhaps it was a final visit to a fondly remembered haunt, but with hindsight, said Mr Allan, "It was a clear indication that something was up". Tragically for Boston and the four people who lost their lives, when two homemade bombs tore in the crowds watching the annual marathon, no-one had foresaw quite what.
