BOSTON — A former brother-in-law of Boston Marathon bomber Dzhokhar Tsarnaev testified Wednesday from Kazakhstan about the role of a conservative Muslim convert who steered Tsarnaev’s older brother toward a stricter version of Islam.

Elmirza Khozhugov, the former husband of Tsarnaev’s sister Ailina Tsarnaeva, testified on live video for the defense from Almaty, the largest city in Kazakhstan. The Tsarnaev family – ethnic Chechens – lived in the former Soviet republic of Kyrgyzstan before moving to the U.S. when Dzhokhar was 8.

A federal jury will soon decide whether Dzhokhar, 21, should be executed or sentenced to life in prison for the 2013 bombings that killed three people and wounded more than 260.

The defense is trying to show that Dzhokhar was heavily influenced by his radicalized 26-year-old brother, Tamerlan, whom they call the mastermind of the plot. Tamerlan was killed days after the bombing during a getaway attempt.

Khozhugov said the Muslim convert named Misha often visited the Tsarnaev apartment in Cambridge, Massachusetts, to talk to Tamerlan about Islam. “I wouldn’t call it formally a lesson, but he was teaching him and suggesting books to read … expressing his own views about that faith to Tamerlan,” Khozhugov said.

He said Tamerlan told him he quit boxing, stopped taking acting classes, and stopped playing and listening to music after Misha said those activities were not appropriate in Islam.

Khozhugov also described the close-knit relationship between the brothers.

The defense also tried to diffuse an image of Tsarnaev giving the middle finger to a camera in his holding cell the day he was arraigned in the bombing. Deputy U.S. Marshal Kevin Roche testified Tsarnaev apologized when he and his supervisor went to talk to him afterward.