Investigators in the United States are hoping to question the widow of one of the suspects in the Boston marathon bombing.
Katherine Russell-Tsarnaev is the widow of Tamerlan Tsarnaev, who died last week after a shoot-out with police.
Tamerlan and his brother Dzhokhar are believed to have been responsible for the bombs set off at the end of the marathon in the US city of Boston on 15 April.
Police cornered the pair in Watertown, near Boston, on the night of 19 April. A gun battle ensued, leaving Tamerlan dead and Dzhokhar in hospital.
Tamerlan's widow Katherine, 24, has kept a low profile since her husband was killed.
It is believed she is staying with her parents in Rhode Island. She has refused to answer any questions from the media.
The only occasion she has been seen in public is when she entered the home she shared with her husband in Cambridge to pick up some belongings.
But that hasn't stopped some details of her life, and of her relationship with Tamerlan, starting to emerge.
'She was ready to learn'
Katherine Russell, as she then was, grew up in the small town of North Kingstown in Massachusetts.
She was one of three daughters to Warren Russell, a doctor, and his wife Judith.
According to the Associated Press, Katherine Russell's art teacher remembers her as being particularly talented at painting and drawing. "She was very nice and very smart," Amos Trout Paine said. "She was ready to learn."
She was very nice and very smart.
But while she had been brought up as a Christian, she did not seem to be interested in religion. "There was none of that with her," Paine said. "She was neutral."
A change came when she went to Suffolk University in 2007.
While a student, she converted to Islam. She also met her future husband Tamerlan, who she married in June 2010.
Tamerlan and his family had been living in the US since around 2002, having moved from the Russian republic of Dagestan.
Katherine Russell knew nothing about Islam when she met Tamerlan, said her lawyer Amato DeLuca, who added that he didn't know if marriage was a factor in her conversion.
The couple went on to have a daughter, Zahara. All three lived in the Tsarnaev family apartment, which they shared in recent years with Tamerlan's mother, Zubeidat, and father, Anzor, now divorced, along with his brother Dzhokhar.
'She had been working all week to support her family'
According to The Week, Katherine Tsarnaev's lawyer DeLuca claims she had no knowledge of the attacks allegedly carried out by her husband and his brother.
Instead she learned her husband was a suspect in the same way as most Americans: by watching TV coverage of the bombings and their aftermath.
DeLuca added that Katherine Tsarnaev had been working 70-80 hours a week in the healthcare industry while her husband looked after Zahara, adding: "When this allegedly was going on, she was working, and had been working all week to support her family."
Although mystery remains over the motive behind the bombing attacks carried out by Tamerlan and his brother Dzhokhar, it is known that last year Tamerlan spent six months in Dagestan, a mainly Muslim Russian republic bordering Chechnya.
During the visit, he also reportedly spent two days in Chechnya itself.
'I think he kind of brainwashed him'
A different view has been offered by Anne Kilzer, a resident of Belmont, Massachusetts, who used to visit the Tsarnaev home to get beauty treatment from Tamerlan Tsarnaev's mother.
Kilzer said that whenever she visited the apartment, Katherine Tsarnaev was always there with the baby and her mother-in-law. According to the Associated Press, she described Tamerlan as "surly and intimidating".
She met this guy, I guess, and everything changed.
"[Katherine] was a very sweet woman, but I think kind of brainwashed by him," Kilzer said, describing her as "lonely".
She added that she thought the apartment was so cramped and crowded that it "would have been difficult for Tamerlan to hide criminal activity from his wife."
Meanwhile the Daily Telegraph has spoken to neighbours of Warren and Judith Russell, who describe them as being "very nice family, with three lovely daughters who are friendly and well-mannered."
Mr and Mrs Russell had been "very supportive" of their daughter's decision to take up Islam.
And the Daily Mail has tracked down a former classmate, who remembers Katherine as a 16-year-old student: "The thing that's so shocking is that there was nothing at all that made Katherine different. But she met this guy, I guess, and everything changed."