Boston Bomber Obsessed With Islam, Mother-in-Law Says

Boston: The American mother-in-law of the deceased mastermind of the 2013 Boston Marathon bombings described Monday a man obsessed with Islam and politics who insisted she read the Koran.

Nurse Judith Russell, whose daughter Katherine converted to Islam after meeting Tamerlan Tsarnaev, told a court in the northeastern US city that no one in the family went to their wedding.

Russell was a witness called by defense lawyers battling to save Tamerlan's younger brother Dzhokhar Tsarnaev from the death penalty after he was convicted of carrying out the deadly attacks.

Tamerlan was shot dead by police four days after the April 15, 2013 attacks while the brothers, of Chechen descent, were on the run.

The defense launched its bid Monday to persuade a 12-person jury to sentence Dzhokhar Tsarnaev to life without parole in America's most fortified federal jail, not sentence him to death.

Lawyers argue that Dzhokhar, then 19, was under the thrall of his more radical, manipulative and aggressive 26-year-old brother.

Russell told the court her daughter and Tamerlan were not a good match, explaining that he did not work, came across as arrogant and only had one passion: boxing.

Katherine converted to Islam after meeting Tamerlan in a nightclub. She fell pregnant and dropped out of college, and started to cover up and wear the veil.

"Over time, he became more and more religious," Judith Russell said. Tamerlan grew a beard and, after a six-month spell in Russia, returned with a longer beard and hair, she said.

"He always wanted to talk about how Islam was good," Russell said. "It became an obsession."

He harped on about politics, American influence and the "harm" it was doing to Muslim countries, she said.

Shortly after their daughter was born, when Katherine moved back with her parents, Tamerlan went to Russia for six months in 2012.

"I thought it was pretty selfish," Russell said, crying softly as she spoke of tensions with her daughter created by the marriage.

Over time, she stopped talking to Tamerlan, whom she saw only once, briefly, after his return from Russia.

Although her daughter's ordeal was nothing compared to those of the bombing victims, she said Katherine had started to heal and get her life back on track in the last two years.